Low pressure process for synthesis of pt(pf3)4 involving a soluble intermediate and storage of obtained pt(pf3)4

ABSTRACT

A method for synthesizing Pt(PF 3 ) 4  (CAS #19529-53-4) comprises dissolving a platinum compound having a general formula, Pt(Hal) 2 (PF 3 ) x , in an anhydrous solvent forming a Pt(Hal) 2 (PF 3 ) x  solution, wherein Hal=F, Cl, Br or x=1, 2, adding a metal powder and excess amount of PF 3  into the Pt(Hal) 2 (PF 3 ) x  solution, and forming Pt(PF 3 ) 4  through a reaction between Pt(Hal) 2 (PF 3 ) x , PF 3  and the metal powder under a reaction condition. The method further comprises synthesizing Pt(Hal) 2 (PF 3 ) x  through the steps of dispersing a platinum precursor having a general formula, Pt(Hal) 2 , into the anhydrous solvent forming a suspension of Pt(Hal) 2 , wherein Hal=F, Cl, Br or I, introducing PF 3  into the suspension of Pt(Hal) 2 , and forming the solution of the platinum compound Pt(Hal) 2 (PF 3 ) x  in the anhydrous solvent through a reaction of PF 3  and Pt(Hal) 2 .

TECHNICAL FIELD

The present invention relates to synthesis and storage of Pt(PF₃)₄ usedas a precursor in film forming compositions. Pt(PF₃)₄ is synthesizedfrom a platinum compound selected from Pt(Hal)₂ (Hal=F, Cl, Br or I) orPt(Hal)₂(PF₃)_(x) (Hal=F, Cl, Br or I; x=1, 2), a metal powder and PF₃at low pressure in an anhydrous solvent capable of dissolvingPt(Hal)₂(PF₃)_(x), a reaction intermediate, wherein Pt(Hal)₂(PF₃)_(x)may be formed from Pt(Hal)₂ and PF₃. The obtained Pt(PF₃)₄ is thenstored under air and moisture free conditions at room temperature inapparatus and ampoules fabricated from metal such as stainless steel andpreferably having a passivated or electro-polished inner surface.

BACKGROUND

Chemical vapor deposition (CVD) and atomic layer deposition (ALD)methods are gaining significant attentions for fabrication of catalystsand batteries at industrial scales. A proper precursor for a highthroughout-put industrial process should have a high vapor pressure atideally room temperature, to ensure a maximum dosage in the shortesttime and at temperatures that do not compromise the precursor stability.Platinum is widely employed as catalyst and a wide variety of materialscontaining platinum on support are available to the date. Nonetheless,the processes applying deposition of platinum from the vapor phase arerare due to lack of proper platinum precursors.

For instance, platinum hexafluoride (PtF₆, CAS #13693-05-5), a solid atroom temperature, although being volatile at room temperature, is rarelyapplied as deposition precursor due to very strong oxidizing nature andcorrespondingly very strong etching properties. A widely cited fordeposition processes (MeCp)PtMe₃ (CAS #94442-22-5) has 1 Torr vaporpressure at 69° C., but start gradually decomposing at 50° C. (Journalof Vacuum Science & Technology, B; Microelectronics and NanometerStructures (1990), 8(6), 1826-9), precluding utilization of the givencompound for the high throughout-put process.

Complex Pt(PF₃)₄ (CAS #19529-53-4) is a volatile liquid at roomtemperature with the vapor pressure 36 Torr at room temperature (R. D.Sanner et al., Report (1989), (UCRL-53937; Order No. DE90000902)),almost ideal potential precursor for Pt deposition from the vapor phase.However, the compound has a very limited commercial availability. Thereason for non-scalability may be technical difficulties associated withthe synthesis of Pt(PF₃)₄, almost ideal potential precursor for Ptdeposition from the vapor phase. However, the compound has a verylimited commercial availability (only from one supplier in Japan [JapanAdvanced Chemicals, in gram scale) and so far no suitable ALD processhas been reported using this chemical. The reason for non-scalabilitymay be technical difficulties associated with the synthesis of Pt(PF₃)₄at gram scale level and even more difficult in manners that could bescaled up industrially with acceptable yield and realistic operatingconditions.

The original synthesis of Pt(PF₃)₄ in gram scale and yield 70-80% wasperformed by reaction (1) at 100-150 atm. PF₃ and 166° C. applying “fineand oxide free copper powder” (Angew. Chem. Int. Ed. 1965, 4, 521). Thesynthesis recipe is only one sentence in reference and later referencesapplying the same method, without any details on reaction and equipment.This reaction requires applying PF₃ gas onto a mixture of two solids(PtCl₂ and Cu powder) at high pressure and is barely scalable for theskilled-in-the-art chemists.

PtCl₂+2Cu+PF₃ (excess)=Pt(PF₃)₄+2CuCl   (1)

Notable that the reaction of PtCl₂ and PF₃ (2) at 60-80° C. and underthe undisclosed pressure afforded Pt(PF₃)₄ only in 1% yield (Inorg.Nucl. Chem. Letters, Vol. 4, pp. 275-278, 1968). Such low yield makesthis approach impossible to implement for industrial applications.

PtCl₂+PF₃ (excess)→Pt(PF₃)₄+other products   (2)

The flow reaction (3) from the same starting compounds under theundisclosed pressure produced only donor-acceptor adducts (Inorg. Nucl.Chem, Letters, Vol. 4, pp. 275-278, 1968).

3PtCl₂+PF₃ (excess)→PtCl₂(PF₃)₂+[PtCl₂(PF₃)]₂   (3)

Compounds PtCl₂(PF₃)₂ and [PtCl₂(PF₃)]₂ were synthesized from solidPtCl₂ and PF₃ gas (J. Chatt, A. A. Williams, J. Chem. Soc. [London]1951, 3061). Solid compounds may react with PF₃ under the undisclosed“higher” pressure forming Pt(PF₃)₄, according to one sentence on page200 of Zeitschrift fur Anorganische und Allgemeine Chemie, Band 364,1969, p 192-208. One may assume that the “higher pressure” is 40-150 atmsince this range is reported in Zeitschrift fur Anorganische undAllgemeine Chemie, Band 364, 1969, p 192-208 for synthesis of Pt(PF₃)₄.Compound PtCl₂(PF₃)₂ is soluble in a polar solvent CDCl₃ and its NMR wasreported by J. Chem. Res., Syn., 1981, 2, 38. Solubility of PtCl₂(PF₃)₂in benzene was reported to be “low” and the molar concentrations were0.005-0.01M and melting point of PtCl₂(PF₃)₂ is 118.3° C. by J. Chem.Soc. [London] 1951, 3061. FTIR spectra of PtCl₂(PF₃)₂ is disclosed inJournal of Chemical Research, Synopses (1981), (2), 37.

Alternatively, preparation of Pt(PF₃)₄ achieved in a rarely availablerotating autoclave in gram scale by reaction (4) under 40 atm of PF₃with the 95% yield (Zeitschrift fur Anorganische und Allgemeine Chemie.Band 364. 1969, 192-208).

PtCl₄+4Cu+4PF₃→Pt(PF₃)₄+4CuCl   (4)

PtCl₄+6PF₃→Pt(PF₃)₄+2PF₃Cl₂   (5)

It is notable that the reaction without copper (5) produces PF₃Cl₂,which complicates purification of Pt(PF₃)₄ due to comparable volatility(Zeitschrift fur Anorganische und Allgemeine Chemie. Band 364. 1969,192-208). Although addition of copper reduces amount of PF₃Cl₂, thisimplies that reactions (4) and (5) may afford impure Pt(PF₃)₄, whichdoes not meet the quality standards for CVD and ALD precursors.Noteworthy, reaction (4) also requires mixing two solids and contactingthem with PF₃ gas, raising already mentioned scalability concerns. Thereaction of PtCl₄ with excess PF₃ makes the scale-up even lessrealistic.

RU 247857602 discloses a two-step process under 2-6.3 MPa (19.7-62.2atm) of PF₃ (6a and 6b), where CuO is reduced in the same autoclaveprior to introduction of K₂PtCl₆ and PF₃.

CuO+H₂→Cu+H₂O   (6a)

K₂PtCl₆+4Cu+PF₃ (excess)→Pt(PF₃)₄+4CuCl+2KCl   (6b)

RU 220146301, U.S. Pat. No. 7,044,995B2, Terekhov et al. (Terekhov etal., International Symposium on Recycling of Metals and EngineeredMaterials, Proceedings, 4^(th), Oct. 22-25, 2000, pp. 487-491) andKovtun et al. (Publications of the Australasian Institute of Mining andMetallurgy (2002), 2/2002, 367-372) disclose a platinum extraction fromore by interaction of “PGM matte” or “raw material” with PF₃ gas forminga volatile Pt(PF₃)₄. The raw materials were assumed to contain Pt metaland interact with PF₃ by (7 d). However, Pt and PF₃ afforded platinumcompound F₅PPt as first reported in 1891 (H. Moissan, Bull. Soc. Chim.France 5, 454 (1891)) and this compound was considered to be analogousto (PCl₃)PtCl₂.

3Pt+4HNO₃+18HCl→3H₂PtCl₆+4NO+8H₂O   (7a)

H₂PtCl₆+2NH₃→(NH₄)₂PtCl₈   (7b)

(NH4)₂PtCl₆+H₂=2NH₄Cl+4HCl+Pt (under ultrasonic irradiation)   (7c)

Pt+PF₃ (excess)→Pt(PF₃)₄   (7d)

In addition, according to Chem. Ber. 101, 138-142 (1968), Pt metal doesnot react with PF₃ at any conditions. U.S. Pat. No. 7,044,995 B2discloses that finely dispersed Pt metal (platinum black, particlessizes <20 μm) does not react with PF₃ and only “activated” Pt metalobtained by the multi-step procedure (7a-7c) and applying the reductionwith hydrogen under the ultrasonic irradiation in step (7c) could reactwith PF₃.

Solvent effect may be negative for reaction starting from PtCl₂, becauseaccording to Zhurnal Neorganicheskoi Khimii (1970), 15(9), 2445-8, incontrast to the neat reaction of PtCl₂+I₂═PtCl₂I₂, reaction of thesereagents in organic solvents gave various products but not PtCl₂I₂.Several classes of solvents react with PF₃, PtCl₂, and reduced Ptspecies, and hence may not be used for synthesis of Pt(PF₃)₄. Theseclasses of the solvents include primary amines, since they react withPF₃ producing RNHPF₂, (RNH)₂PF₂H, and (RNH)₂PF (See J. Chem. Soc. A(1970), (11), 1935-8). Tertiary amines, e.g. NMe₃, NEt₃ are formingadducts with PF₃ (See inorganic Chemistry (1963), 2, 384-8). Alcoholsand PF₃ form organic phosphites (See Transactions of the Illinois StateAcademy of Science (1936), 29 (No. 2), 89-91). General patterns ofreactivity of P(Hal)₃ (Hal=Cl, Br) toward alcohols are well documented.Dienes, olefins, unsaturated aldehydes, ketones reacts with PF₃ formingaddition compounds as was shown for PCl₃ and PBr₃ in (See Uspekhi Khimii(1968), 37(5), 745-77). Acetone reacts with PF₃ and Pt(II) compounds(See Zhurnal Obshchei Khimii (1975), 45(3), 512-18; Inorganica ChimicaActa (1997), 264(1-2), 297-303). Halocarbons may react with Pt compoundsunder reaction conditions via oxidative addition as was shown inselected examples in Organometallics (2019), 38(10), 2273,Organometallics 2009, 28, 1358-1368; and Organometallics (1987), 6(12),2548]; oxidative addition of alkyl and aryl halides to platinumcomplexes is well documented reaction.

In conclusion, the existing synthesis approaches for Pt(PF₃)₄ stronglydepend on the reaction conditions, while changing in conditions maysignificantly reduce the yield of Pt(PF₃)₄ or afford different productsindicating a lack of robustness of the process, and no synthesis processhas been reported so far requiring a PF₃ pressure inferior to 3 MPa(29.6 atm, 420 psig) as claimed in RU 2478576C2. Most of synthesesrequire special equipment or conditions not commonly available forscaling of processes to large scale, such as high pressure autoclaves.In particular, the existing methods are lacking of technical details anda purity of Pt(PF₃)₄ has not been reported in any references. Further,all the disclosed methods are essentially dry approaches which alsopresent significant challenges for scale-up to industrial scale.

Numeral references for catalytic transformation of hydrocarbons byplatinum compounds exist, such as, Journal of the American ChemicalSociety (2002), 124(42), 12550-12556. A catalytic activity of Ptcompounds was illustrated for model systems Pt₄(PF₃)₈— saturated andaromatic cyclic hydrocarbons in Jackson et al., J. Am. Chem. Soc. 1997,119, 7567-7572. Namely small platinum clusters generated from Pt₄(PF₃)₈react with a variety of saturated and aromatic cyclic hydrocarbons(cyclohexane, benzene, toluene). Jackson et al. illuminate a catalyticand dehydrogenation behavior of platinum. Hence one may assume thatintroduction of a hydrocarbon solvent in the reaction system followed byheating could lead to a mixture of products due to various catalyticreactions and may be considered as not favorable idea for selectivesynthesis of Pt(PF₃)₄. Owing to these reasons, Pt(PF₃)₄ was neversynthesized and operated in organic solvents and only anhydrous HF andSO₂ were applied as solvents to study Pt(PF₃)₄ chemistry (Drews et al.,Chem. Eur. J. 2008, 14, 4280-4286).

It would be a significant advancement to provide a method capable of ascale up production of Pt(PF₃)₄ in a high yield, since up to date apotentially ideal Pt(PF₃)₄ precursor has not applied only due to absenceof scalable method.

SUMMARY

Disclosed is a method for synthesizing Pt(PF₃)₄ (CAS #19529-53-4), themethod comprising the steps of:

-   -   dissolving a platinum compound having a general formula,        Pt(Hal)₂(PF₃)_(x), in an anhydrous solvent forming a        Pt(Hal)₂(PF₃)_(x) solution, wherein Hal=F, Cl, Br or I, x=1, 2;    -   adding a metal powder and excess amount of PF₃ into the        Pt(Hal)₂(PF₃)_(x) solution; and    -   forming Pt(PF₃)₄ through a reaction between Pt(Hal)₂(PF₃)_(x),        PF₃ and the metal powder under a reaction condition. The        disclosed methods may include one or more of the following        aspects:    -   the reaction condition including a reaction temperature ranging        from approximately −120-200° C.;    -   the reaction condition including a reaction temperature ranging        from approximately 30-200° C.;    -   the reaction condition including a reaction temperature ranging        from room temperature to approximately 180° C.;    -   the reaction condition including a reaction temperature ranging        from room temperature to approximately 130° C.;    -   the reaction condition including a reaction temperature ranging        from approximately 80-130° C.;    -   the reaction condition including a reaction pressure ranging        from approximately 10 psig to approximately 3000 psig;    -   the reaction condition including a reaction pressure ranging        from approximately 20 psig to approximately 1000 psig;    -   the reaction condition including a reaction pressure ranging        from approximately 20 to approximately 300 psig;    -   the reaction condition including a reaction pressure below        approximately 300 psig;    -   the anhydrous solvent having a boiling point higher than 150°        C.;    -   the anhydrous solvent having a boiling point higher than 200°        C.;    -   the metal powder being a copper, zinc or aluminum powder;    -   the metal powder being a copper powder;

the metal powder being a zinc powder;

-   -   the metal powder being an aluminum powder;    -   the metal powder having an electrode potential lower than that        of Pt;    -   the metal powder not interacting with PF₃ and not forming        complexes with PF₃ under the reaction conditions;    -   the metal powder having a proper particle size range allowing it        to stay in a powder form during the reaction process;    -   the metal powder having a particle size ranging from 200-900        microns;    -   the metal powder having a particle size ranging from 300-500        microns;    -   further comprising the step of        -   synthesizing the platinum compound Pt(Hal)₂(PF₃)_(x) (Hal=F,            Cl, Br or I; x=1, 2) that includes the steps of;            -   dispersing a platinum precursor having a general                formula, Pt(Hal)₂, into the anhydrous solvent forming a                suspension of Pt(Hal)₂, wherein Hal=F, Cl, Br or I;            -   introducing PF₃ into the suspension of Pt(Hal)₂; and            -   forming the solution of the platinum compound                Pt(Hal)₂(PF₃)_(x) (Hal=F, Cl, Br or I; x=1, 2) in the                anhydrous solvent therefrom through a reaction of PF₃                and Pt(Hal)₂;    -   the platinum precursor Pt(Hal)₂ being anhydrous;    -   the platinum precursor Pt(Hal)₂ being PtCl₂;    -   the platinum precursor Pt(Hal)₂ being anhydrous PtCl₂;    -   the platinum compound Pt(Hal)₂(PF₃)_(x) (Hal=F, Cl, Br or I,        x=1, 2) being anhydrous;    -   the platinum compound Pt(Hal)₂(PF₃)_(x) (Hal=F, Cl, Br or I,        x=1, 2) being PtCl₂(PF₃)₂;    -   the platinum compound Pt(Hal)₂(PF₃)_(x) (Hal=F, Cl, Br or I,        x=1, 2) being anhydrous PtCl₂(PF₃)₂;    -   further comprising the steps of:

purifying Pt(PF₃)₄ in a trap made of metal under air and moisture freeconditions; and

storing the purified Pt(PF₃)₄ under air and moisture free conditions ina container made of the metal,

wherein the step of storing includes the steps of

-   -   removing moisture from the inner surface of the container; and    -   electro-polishing the inner surface of the container, or    -   passivating the container with PF₃ before introducing the        purified Pt(PF₃)₄;    -   the metal for the trap being selected from carbon steel,        stainless steel, or stainless steel 316 alloy, respectively;    -   the metal for the container being selected from carbon steel,        stainless steel, or stainless steel 316 alloy, respectively;    -   the anhydrous solvent being a hydrocarbon solvent;    -   the hydrocarbon solvent being selected form an oxyhydrocarbon        solvent having a general formula (C_(n)H_(2n+1))₂O (n≥1) and        H₃C(O(CH₂)₂)_(n)OCH₃ (n≥1);    -   the hydrocarbon solvent being selected form an arene solvent        having a general formula (C_(n)H_(2n+1))_(x)C₆H_(6−x) (x≥1,        n≥1);    -   the hydrocarbon solvent being selected form an alkane solvent        having a general formula C_(n)H_(2n+2) (n≥1);    -   the anhydrous solvent being a dried alkane solvent selected from        decane, di-, tri-, tetra, penta- and hexadecane, the like;    -   the anhydrous solvent being a dried arene solvent selected from        xylene, mesithylene, cymene, pentylbenzene, diisopropylbenzene,        diisobutylbenzene, or the like;    -   the anhydrous solvent being a dried ether solvent selected from        dibutyl ether, dihexyl ether, dioctyl ether, dimethyl ether of        diethylene glycol, triethylene glycol dimethyl ether,        tetraethylene glycol dimethyl ether or the like;    -   the anhydrous solvent being an arene solvent selected from        xylene, mesithylene, cymene, pentylbenzene, diisopropylbenzene,        diisobutylbenzene or the like;    -   the dried ether solvent being preferably dibutyl ether, dihexyl        ether, dioctyl ether, triethylene glycol dimethyl ether,        tetraethylene glycol dimethyl ether;    -   the dried arene solvent being preferably xylene, mesithylene,        cymene, pentylbenzene, diisopropylbenzene, diisobutylbenzene;    -   the dried alkane solvent being preferably di-, tri-, tetra,        penta- and hexadecane as well as a mixture of alkanes known as a        mineral oil;    -   the anhydrous solvent being capable of dissolving the reaction        intermediate;    -   the anhydrous solvent being capable of dissolving        Pt(Hal)₂(PF₃)_(x) (Hal=F, Cl, Br or I, x=1, 2);    -   the anhydrous solvent being capable of dissolving PtCl₂(PF₃)₂);    -   the anhydrous solvent not reacting with Pt(PF₃)₄;    -   the anhydrous solvent not reacting with Pt(Hal)₂ (Hal=F, Cl, Br        or I);    -   the anhydrous solvent not reacting with PtCl₂;    -   the anhydrous solvent being xylene;    -   the anhydrous solvent being hexadecane;    -   a yield of Pt(PF₃)₄ being in a range of approximately 70-99.9%;    -   a yield of Pt(PF₃)₄ being in a range of approximately 70-95%;    -   a yield of Pt(PF₃)₄ being in a range of approximately 70-93%;    -   a purity of Pt(PF₃)₄ being more than 99% by weight;    -   a purity of Pt(PF₃)₄ being more than 99.5% by weight;    -   a purity of Pt(PF₃)₄ being approximately 90-99.9% by weight;    -   a purity of Pt(PF₃)₄ being approximately 99.0-99.9% by weight;    -   a purity of Pt(PF₃)₄ being approximately 99.5-99.9% by weight;        and    -   the formed Pt(PF₃)₄ being scalable to large industrial scale.

Also, disclosed is a method for manufacture and storage of Pt(PF₃)₄ (CAS#19529-53-4), the method comprising the steps of:

a) forming a suspension of a platinum precursor Pt(Hal)₂, wherein Hal=F,Cl, Br or I, and a metal powder in an anhydrous solvent;

b) introducing excess amount of PF₃ into the suspension of Pt(Hal)₂ andthe metal powder;

c) forming a soluble reaction intermediate Pt(Hal)₂(PF₃)_(x) in theanhydrous solvent through a reaction of PF₃ and Pt(Hal)₂, wherein Hal=F,Cl, Br or I; x=1, 2, under a low pressure condition;

d) forming Pt(PF₃)₄ from a reaction between Pt(Hal)₂(PF₃)_(x), the metalpowder and PF₃ in the anhydrous solvent;

e) purifying Pt(PF₃)₄ under air and moisture free conditions in a trapmade of metal; and

f) storing the purified Pt(PF₃)₄ under the air and moisture freeconditions in a container made of the metal. The disclosed method mayinclude one or more of the following aspects:

-   -   the platinum precursor Pt(Hal)₂ being PtCl₂;    -   the anhydrous solvent having a boiling point higher than 150°        C.;    -   the anhydrous solvent having a boiling point higher than 200°        C.; the anhydrous solvent being a hydrocarbon solvent selected        form an oxyhydrocarbon solvent having a general formula        (C_(n)H_(2n+1))₂O (n≥1) and H₃C(O(CH₂)₂)_(n)OCH₃ (n≥1), an arene        solvent having a general formula (C_(n)H_(2n+1))_(x)C₆H_(6−x)        (x≥1, n≥1) or an alkane solvent having a general formula        C_(n)H_(2n+2) (n≥1)    -   the anhydrous solvent being xylene or hexadecane;    -   the anhydrous solvent being capable of dissolving the reaction        intermediate;    -   the anhydrous solvent being capable of dissolving        Pt(Hal)₂(PF₃)_(x) (Hal=F, Cl, Br or I, x=1, 2);    -   the anhydrous solvent being capable of dissolving PtCl₂(PF₃)₂);    -   the anhydrous solvent not reacting with Pt(PF₃)₄;    -   the anhydrous solvent not reacting with Pt(Hal)₂ (Hal=F, Cl, Br        or I);    -   the anhydrous solvent not reacting with PtCl₂;    -   a reaction temperature ranging from approximately 30-200° C.;    -   a reaction temperature ranging from approximately 80-130° C.;    -   the low pressure condition being a pressure below about 300        psig;    -   the low pressure condition being a pressure ranging from        approximately 20 to 300 psig;    -   the metal powder being a copper, zinc or aluminum powder;    -   the metal powder being a copper powder;    -   the metal powder having an electrode potential lower than that        of Pt;    -   the metal powder not interacting with PF₃ and not forming        complexes with PF₃ under the reaction conditions;    -   the metal powder having a proper particle size range allowing it        to stay in a powder form during the reaction process;    -   the metal powder having a particle size ranging from 200-900        microns;    -   the metal powder having a particle size ranging from 300-500        microns;    -   a yield of Pt(PF₃)₄ being in the range of approximately        70-99.9%;    -   a yield of Pt(PF₃)₄ being in a range of approximately 70-95%;    -   a yield of Pt(PF₃)₄ being in a range of approximately 70-93%;    -   a purity of Pt(PF₃)₄ being approximately 90-99.9 wt. % after        purification;    -   a purity of Pt(PF₃)₄ being 99.0-99.9 wt. % after purification;    -   the metal for the trap and the metal for the container being        selected from carbon steel, stainless steel, or stainless steel        316 alloy, respectively; and    -   further comprising the steps of:        -   electro-polishing the inner surface of the container, or        -   passivating the container with PF₃ before introducing of the            purified Pt(PF₃)₄.

Also, disclosed is a method for manufacture and storage of Pt(PF₃)₄ (CAS#19529-53-4), the method comprising the steps of:

a) forming a suspension of a platinum precursor Pt(Cl)₂ in an anhydroussolvent selected form xylene or hexadecane;

b) introducing excess amount of PF₃ into the suspension of Pt(Cl)₂ toform a solution of Pt(Cl)₂(PF₃)_(x) (x=1, 2) in the anhydrous solventtherefrom through a reaction of PF₃ and Pt(Cl)₂;

c) adding a copper powder into the solution of Pt(Cl)₂(PF₃)_(x) (x=1,2);

d) forming Pt(PF₃)₄ from a reaction between the copper powder, PF₃ andPt(Cl)₂(PF₃)_(x) in the anhydrous solvent in a reaction temperatureranging from 30-200° C. and a reduced PF₃ pressure ranging from 20 to300 psig;

e) purifying Pt(PF₃)₄ under air and moisture free conditions in a trapmade of stainless steel; and

f) storing the purified Pt(PF₃)₄ under the air and moisture freeconditions in a container made of the stainless steel, wherein the innersurface of the container is electro-polished or passivated with PF₃. Thedisclosed method may include one or more of the following aspects:

-   -   the copper powder having a particle size ranging from 200-900        microns; and    -   the copper powder having a particle size ranging from 300-500        microns.

NOTATION AND NOMENCLATURE

The following detailed description and claims utilize a number ofabbreviations, symbols, and terms, which are generally well known in theart. While definitions are typically provided with the first instance ofeach acronym, such as, stainless steel (SS). Certain abbreviations,symbols, and terms are used throughout the following description andclaims, and include the followings.

The following detailed description and claims utilize a number ofabbreviations, symbols, and terms, which are generally well known in theart.

As used herein, the indefinite article “a” or “an” means one or more.

As used herein, “about” or “around” or “approximately” in the text or ina claim means±10% of the value stated.

As used herein, “room temperature” in the text or in a claim means fromapproximately 18° C. to approximately 25° C.

As used herein, “atmospheric pressure” in the text or in a claim meansapproximately 1 atm.

The standard abbreviations of the elements from the periodic table ofelements are used herein. It should be understood that elements may bereferred to by these abbreviation (e.g., Si refers to silicon, N refersto nitrogen, O refers to oxygen, C refers to carbon, H refers tohydrogen, Hal refers to halogens, which are F, Cl, Br, I).

The unique CAS registry numbers (i.e., “CAS”) assigned by the ChemicalAbstract Service are provided to identify the specific moleculesdisclosed.

As used herein, the term “hydrocarbon” refers to a saturated orunsaturated function group containing exclusively carbon and hydrogenatoms.

As used herein, the term “low pressure”, “low reaction pressure” or “lowPF₃ pressure” refers to a pressure below 300 psig or below 20 atm. Thesame applies to “reduced pressure” that refers to a pressure reduced orlowered to below 300 psig or 20 atm. In some cases, “low pressure”, “lowreaction pressure” or “low PF₃ pressure” may refer to a pressure rangeranging from 20 psig to 300 psig.

Ranges may be expressed herein as from about one particular value,and/or to about another particular value. When such a range isexpressed, it is to be understood that another embodiment is from theone particular value and/or to the other particular value, along withall combinations within said range. Any and all ranges recited hereinare inclusive of their endpoints (i.e., x=1 to 4 or x ranges from 1 to 4includes x=1, x=4, and x=any number in between), irrespective of whetherthe term “inclusively” is used.

Reference herein to “one embodiment” or “an embodiment” means that aparticular feature, structure, or characteristic described in connectionwith the embodiment may be included in at least one embodiment of theinvention. The appearances of the phrase “in one embodiment” in variousplaces in the specification are not necessarily all referring to thesame embodiment, nor are separate or alternative embodiments necessarilymutually exclusive of other embodiments. The same applies to the term“implementation.”

As used in this application, the word “exemplary” is used herein to meanserving as an example, instance, or illustration. Any aspect or designdescribed herein as “exemplary” is not necessarily to be construed aspreferred or advantageous over other aspects or designs. Rather, use ofthe word exemplary is intended to present concepts in a concretefashion.

Additionally, the term “or” is intended to mean an inclusive “or” ratherthan an exclusive “or”. That is, unless specified otherwise, or clearfrom context, “X employs A or B” is intended to mean any of the naturalinclusive permutations. That is, if X employs A; X employs B; or Xemploys both A and B, then “X employs A or B” is satisfied under any ofthe foregoing instances. In addition, the articles “a” and “an” as usedin this application and the appended claims should generally beconstrued to mean “one or more” unless specified otherwise or clear fromcontext to be directed to a singular form.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and various other aspects, features, and advantages of thepresent invention, as well as the invention itself, may be more fullyappreciated with reference to the following detailed description of theinvention when considered in connection with the following drawings. Thedrawings are presented for the purpose of illustration only and are notintended to be limiting of the invention, in which:

FIG. 1 is a block diagram of exemplary disclosed system of synthesizingPt(PF₃)₄;

FIG. 2 a is a flowchart of an exemplary disclosed process ofsynthesizing Pt(PF₃)₄ starting with Pt(Hal)₂ (Hal=F, Cl, Br or I);

FIG. 2 b is a flowchart of an exemplary disclosed process ofsynthesizing Pt(PF₃)₄ starting with Pt(Hal)₂(PF₃)_(x) (x=1, 2; Hal=F,Cl, Br or I);

FIG. 3 is ¹⁹F NMR spectra of PtCl₂(PF₃)₂ crystals and supernatanthexadecane solution of reaction mixture stopped on the stagePtCl₂(PF₃)₂; and

FIG. 4 is a graph for the Pt(PF₃)₄ assay and relative amount ofimpurities over time in an electro-polished stainless-steel miniaturecanister at room temperature.

DESCRIPTION OF PREFERRED EMBODIMENTS

Disclosed are methods for synthesis, producing, manufacture and storageof Pt(PF₃)₄ (CAS #19529-53-4). The disclosed methods are capable of ascale up production of Pt(PF₃)₄ in a high yield and the producedPt(PF₃)₄ may be used as a precursor for Pt-containing film deposition inmicroelectronic devices or in catalyst industries.

The disclosed synthesis methods may be a 2-steps wet synthesis ofPt(PF₃)₄ using insoluble platinum compound Pt(Hal)₂ (Hal=F, Cl, Br or I)and a soluble reaction intermediate, a platinum compoundPt(Hal)₂(PF₃)_(x) (Hal=F, Cl, Br or I; x=1, 2), which includes formationof the soluble reaction intermediate from the insoluble Pt(Hal)₂ (Hal=F,Cl, Br or I) suspension in low pressure conditions and a reaction of thesoluble intermediate with a metal powder and a co-reactant, such as PF₃,to form Pt(PF₃)₄.

Alternatively, since the soluble intermediate Pt(Hal)₂(PF₃)_(x) (Hal=F,Cl, Br or I; x=1, 2) can be isolated and purified, the disclosedsynthesis methods may be a 1-step wet synthesis of Pt(PF₃)₄ using thesoluble Pt(Hal)₂(PF₃)_(x) (Hal=F, Cl, Br or x=1, 2) to react with ametal powder and a co-reactant, such as PF₃, to form Pt(PF₃)₄ undercertain reaction conditions. Preferably, Hal=Cl. Preferably, a metalpowder is a copper powder.

Furthermore, the disclosed are robust, high yield and scalable synthesesof Pt(PF₃)₄, which may proceed under a low pressure and may be performedin common reactors or apparatus. More specifically, Pt(PF₃)₄ may besynthesized from a platinum compound selected from Pt(Hal)₂ (Hal=F, Cl,Br or I) or Pt(Hal)₂(PF₃)_(x) (Hal=F, Cl, Br or I; x=1, 2), with PF₃ anda metal powder, such as a copper powder, under a low PF₃ pressure, in ananhydrous solvent. The metal powder may have a particle size rangingfrom approximately 200-900 microns, preferably from approximately300-500 microns. The anhydrous solvent may be capable of dissolvingPt(Hal)₂(PF₃)_(x) (Hal=F, Cl, Br or I; x=1, 2), a reaction intermediate,in which Pt(Hal)₂(PF₃)_(x) (Hal=F, Cl, Br or I; x=1, 2) may form fromPt(Hal)₂ and PF₃ under the certain reaction conditions, such as under alow pressure condition. Herein, the platinum compound Pt(Hal)₂(PF₃)_(x)(Hal=F, Cl, Br or I; x=1, 2) can be isolated and purified for using as areactant or a starting material for synthesis of Pt(PF₃)₄. A yield ofPt(PF₃)₄ using the disclosed synthesis methods may be in a range ofapproximately 70-99.9%. The disclosed also includes purificationprocesses of the product Pt(PF₃)₄ through metal traps and storageconditions of the purified Pt(PF₃)₄ in a vessel. Pt(PF₃)₄ may be storedunder air and moisture free conditions in apparatus and ampoulesfabricated from stainless steel and preferably having a passivated orelectro-polished inner surface. Pt(PF₃)₄ may be stored in a metal vesselat room temperature without changing of its purity, such as a stainlesssteel vessel and an inner surface passivated or electro-polishedstainless steel vessel.

As described above, the absence of scalable method in the art may bebecause commonly available reactors for pilot plant syntheses and highvolume manufactures are not designed to operate under a high pressureand not designed for efficient stirring (mixing) of air sensitivesolids. Namely, commercially available (e.g. from High PressureEquipment Company) reactors capable of operation under a high pressureabout 100 atm do not have a stirring capability, which is essential forreaction to proceed. In addition, commercially available reactors (e.g.from Buchiglas USA) are difficult to cool down to even dry icetemperature necessary to condense PF₃ in the reactor. Stirring of solidscould be improved to some extend using a specially designed stirringshafts, but would not solve a parasitic reaction, such as PtCl₂/Cu,which leads to platinum metal and reduces the yield of Pt(PF₃)₄. Inaddition, impurities are difficult to remove, requiring expensive anduncertain additional purification steps.

The disclosed methods for a robust, high yield and scalable synthesis ofPt(PF₃)₄ may proceed under a low PF₃ pressure, e.g., below 20 atm, andmay be performed on commonly used commercially available reactors. Thedisclosed method is a significant advancement in the art to provide amethod capable of producing a scale-up production of Pt(PF₃)₄with a highyield, since up to date a potentially ideal Pt(PF₃)₄ precursor has notapplied only due to the absence of a scalable synthesis method. Thereason of the absence of the scalable synthesis method is that commonlyused commercially available reactors for pilot plant syntheses and highvolume manufacture are not designed for operation under a high pressure(e.g., 30 atm or higher) and not designed for efficient stirring(mixing) of air sensitive solids, as stated above.

The disclosed methods may have proven for the first time that reactionaimed for synthesis of Pt(PF₃)₄ with PtCl₂+PF₃+Cu in a solvent goesthrough the sufficiently soluble intermediate PtCl₂(PF₃)₂ at reactionconditions (e.g., low pressure from 20 to 300 psig and temperature from80 to 130° C.), when starting materials Pt(Hal)₂ (Hal=F, Cl, Br or I) isPtCl₂ and the metal powder is a Cu powder. A common knowledge is thatsolubility of inorganic compound such as PtCl₂(PF₃)₂ is lower insaturated hydrocarbon solvent than in arene solvent benzene and hencecounting on solubility in hydrocarbon solvent hexadecane iscounterintuitive as well as counting on reaction with such lowsolubility even in an arene solvent.

Pt(PF₃)₄ was normally prepared from PtCl₂, K₂PCl₆ and K₂PtCl₆ accordingto the prior art, while K₂PtCl₆ is required to lower PF₃ pressure. BothPtCl₂ and K₂PtCl₆ are insoluble in the disclosed solvents (e.g., arenes,saturated hydrocarbons). As shown in the examples and comparativeexamples that follow, the solvent effects are not similar for platinumstarting compounds, e.g. for PtCl₂ (Example 1, Table 1, comparativeexample 1) and for K₂PtCl₆ (Example 7, Table 5). While addition of thedisclosed solvent (e.g., xylene, hexadecane) is beneficial for reactionstarting from PtCl₂, the neat reaction without solvent with startingcompound K₂PtCl₆:

K₂PtCl₆ Cu(excess)+PF₃ (excess)→Pt(PF₃)₄+4CuCl+2KCl

has a higher yield of Pt(PF₃)₄ than the reaction starting from K₂PtCl₆in the solvent hexadecane, showing that the solvent benefit isbeneficial to certain Pt precursors such as PtCl₂, PtF₂, PtI₂, PtBr₂ orthe like. Hence using solvent for the synthesis of Pt(PF₃)₄ fromPt(Hal)₂ (Hal=F, Cl, Br or I) is novel.

FIG. 1 is a block diagram of an exemplary disclosed solid-gasPtCl₂+PF₃+Cu system for synthesis of Pt(PF₃)₄. As shown, at first, ametal powder, such as Cu powder 11 is added to reactor 16 through line101. Anhydrous solvents are used as solvent 14 in the disclosed process.The applied solvents for solvent 14 may have moisture from 0 to 50 ppm,preferably from 0 to 10 ppm of moisture, more preferably 0 to 1 ppm ofmoisture. Solvent 14 may be dried by contacting with a drying agentselected from 3 Å or 4 Å molecular sieves or an activated aluminathrough drying process 104. Drying process 104 could be done at atemperature range from 10-50° C., preferably at room temperature, within0.5 hours to 20 hours. In some embodiments, drying process 104 may beachieved by keeping the solvent with the molecular sieves in container15 or by passing through a column (not shown) with a drying agent indrying process 104. The moisture content in container 15 after dryingmay be determined by Karl Fischer titration or any other suitableanalysis. Solvent 14 may be a commercially available solvent and may bedegassed by applying vacuum-inert gas cycles or by passing the inert gaswith less than 0.5 ppm of O₂ and moisture before contacting with thedrying agent. Solvent or anhydrous solvent 14 may be stored in container15 or directed to reactor 16 via line 105 right after drying process104. Container 15 with the dried anhydrous solvent 14 could be storedbefore the next step, or transported to other place where reactor 16 islocated.

Afterward, PtCl₂ 12 is charged into reactor 16 under an inert atmosphere(e.g., nitrogen, argon, helium) by any suitable means, e.g. applyingsolid addition funnel 102. PtCl₂ 12 may be anhydrous PtCl₂. In thefollowing, PF₃ 13 is charged into reactor 16 via addition line 103 bypressure difference, while reactor 16 may be pre-vacuumed and heated, orat room temperature and pre-vacuumed, or containing PF₃ at a certainpressure and temperature. Reactor 16 may be vacuumed up to 0.1-50 Torr,preferably up to 0.1-2 Torr to remove the inert gas selected fromnitrogen, argon, helium, before addition of PF₃. Absence of thenon-condensable gas (nitrogen, argon, helium) in reactor 16 will makedistillation of the product Pt(PF₃)₄ more efficient. Alternatively, PF₃added to reactor 16 may contain 1 atm of nitrogen, argon or helium atroom temperature. The addition of PF₃ 13 in reactor 16 creates a PF₃pressure from 20 psig to 300 psig in reactor 16. PF₃ may be added byportions or continuously during the process. The value of the PF₃pressure depends on the pressure rating of the applied reactor and maybe added by portions or continuously during the process and recycledafter the process.

Reactor 16 may be a typical vessel with means of agitation, temperatureand pressure controls and reaction monitoring, applied to synthesis andpurification of Pt(PF₃)₄. Reactor 16 has a cooling and heating devicethat is maintained at a temperature ranging from approximately −120° C.to approximately 200° C., preferably from room temperature to 180° C.,more preferably from room temperature to 130° C., and the correspondingpressure from approximately 10 psig to approximately 3000 psig,preferably from approximately 20 psig to approximately 1000 psig, morepreferable from approximately 20 psig to approximately 300 psig. Reactor16 is connected to an empty vessel serving as ballast and has a vent tovent the reaction content if over pressurized. Reactor 16 is connectedto a nitrogen and vacuum line (not shown) and a PF₃ scrubber (not shown)as well as traps 18 and 20 for collection of the product Pt(PF₃)₄through line 107 and recycling unreacted PF₃ through line 110.

Solvent 14 may include various organic solvents. In some embodiments,solvent 14 may be a dried alkane solvent selected from decane, di-,tri-, tetra, penta- or hexadecane. In this case, Cu powder 11, anhydrousPtCl₂ 12, and dried alkane solvent 14 are loaded in reactor 16 forming asuspension. The starting amount of PtCl₂ solid in solvent 14 is from 1%to 50%, preferably from 5% to 40%, more preferably from 20% to 30%. Themolar ratio of the PtCl₂ 12 to Cu powder 11 is from 1:2 to 1:20,preferably from 1:6 to 1:10. That is, the molar ratio of the Pt to Cu isfrom 1:2 to 1:20, preferably from 1:6 to 1:10. Reactor 16 is vacuumed to0.1-50 Torr, preferably to 0.2-5 Torr prior to introducing of PF₃ 13.

Alternatively, solvent 14 may be a dried arene solvent selected fromxylene, mesithylene, cymene, pentylbenzene, diisopropylbenzene, ordiisobutylbenzene. In this case, Cu powder 11, anhydrous PtCl₂ 12, anddried arene solvent 14 are loaded in reactor 16. The starting amount ofPtCl₂ solid in solvent is from 1% to 50% preferably from 10 to 40%, morepreferably from 20% to 30%. The molar ratio of the PtCl₂ to Cu is from1:2 to 1:20, preferably from 1:6 to 1:10. That is, the molar ratio ofthe Pt to Cu is from 1:2 to 1:20, preferably from 1:6 to 1:10. Reactor16 is vacuumed to 0.1-50 Torr preferably to 0.2-5 Torr prior tointroducing of PF₃ 13.

Alternatively, solvent 14 may be a dried ether solvent selected fromdibutyl ether, dihexyl ether, dioctyl ether, dimethyl ether ofdiethylene glycol, triethylene glycol dimethyl ether, tetraethyleneglycol dimethyl ether. In this case, Cu powder 11, anhydrous PtCl₂ 12,and dried ether solvent 14 are loaded in reactor 16. The starting amountof PtCl₂ solid in solvent is from 1% to 50% preferably from 10 to 40%,more preferably from 20% to 30%. The molar ratio of the PtCl₂ to Cu isfrom 1:2 to 1:20, preferably from 1:6 to 1:10. That is, the molar ratioof the Pt to Cu is from 1:2 to 1:20, preferably from 1:6 to 1:10.Reactor 16 is vacuumed to 0.1-50 Torr, preferably to 0.2-5 Torr prior tointroducing of PF₃ 13.

After introducing PF₃ 13 into reactor 16, a reaction mixture initiallyis a suspension of PtCl₂ 12 and Cu powder 11 in solvent 14 under thepressure of PF₃ 13. Then heating reactor 16 with stirring the reactionmixture, PtCl₂(PF₃)_(x) (x=1, 2) are formed in a temperature range from20 to 120° C., preferably in a temperature range from 90-120° C. Thereaction may be stopped after 20-80 minutes of heating with stirring inabove preferred temperature ranges and PtCl₂(PF₃)₂ may be isolated fromthe solvent, reaction byproducts, residual PF₃, etc. CompoundsPtCl₂(PF₃)_(x) (x=1, 2) are soluble in solvent 14 that may be proven bymeans of NMR spectroscopy, as shown in FIG. 3 . The reaction continuesin reactor 16 under the pressure of PF₃ while PF₃ and PtCl₂(PF₃)_(x)(x=1, 2) are dissolved in the solvent and react with copper powder 11.During the course of reaction, PF₃ 13 is consumed. PF₃ 13 could be addedby portions in reactor 16 or continuously maintain a constant selectedpressure. When all starting and intermediate platinum compounds areconsumed, the pressure in reactor 16 becomes constant at a giventemperature.

The reaction time may be in the range of 1 hour to 24 hours, preferablyfrom 4 hours to 8 hours. The degree of conversion may be monitored by aconsumption rate of PF₃ and pressure change in reactor 16 throughin-situ Raman spectroscopy or any other suitable technique.

In some embodiments, the reaction in reactor 16 occurs in hexadecane,under 20 to 50 psig of PF₃, at the temperatures 100 to 125° C. andfinished in 6 hours. Alternatively, in some embodiments, the reaction inreactor 16 occurs in xylenes, under 20 to 40 psig of PF₃, at thetemperatures from 100 to 125° C. and finished in 5 hours.

After the reaction finishes, the reaction mixture is cooled to 20 to 65°C., preferably 30 to 45° C. The remaining gases consisting of PF₃,Pt(PF₃)₄ and solvent are directed to pre-vacuumed trap 17 maintained ina temperature ranging from −196° C. to −160° C. PF₃ (melting point−151.5° C., boiling point −101.9° C.) and Pt(PF₃)₄ (melting point −15°C.) and the solvent are condensed in pre-vacuumed trap 17. At the end ofPt(PF₃)₄ condensation in pre-vacuumed trap 17, vacuum may be applied inperiods to remove the residual gases such as nitrogen, argon, helium, tocreate a vacuum in the range of 0.1 to 50 Torr, preferably 0.2 to 2 Torrin order to facilitate the distillation of remaining Pt(PF₃)₄ fromreactor 16 in pre-vacuumed trap 17. Pre-vacuumed trap 17, Pt(PF₃)₄ trap18 and PF₃ trap 20 are pre-vacuumed to 0.01-10 Torr, preferably to 0.1-1Torr before condensing the reaction products including Pt(PF₃)₄ and PF₃.

Alternatively to the procedure described above, after the reactionfinishes, the reaction mixture is cooled down to 20-65° C., preferablyto 30-45° C. and a portion of gases containing PF₃, Pt(PF₃)₄ and solventis directed to pre-vacuumed trap 17 through line 106 maintained in atemperature ranging from −60 to −80° C. PF₃ is not condensed, whilePt(PF₃)₄ and solvent are condensed in pre-vacuumed trap 17. AfterPt(PF₃)₄ and solvent are condensed in pre-vacuumed trap 17, thenon-condensed PF₃ is directed by pressure difference from pre-vacuumedtrap 17 to PF₃ trap 20 maintained in a temperature ranging from −160 to−196° C., then the next portion of gases containing PF₃, Pt(PF₃)₄ andsolvent is directed in pre-vacuumed trap 17 from reactor 16 and thecycle continues until all PF₃ is condensed in PF₃ trap 20 and allPt(PF₃)₄ is condensed in pre-vacuumed trap 17.

The condensation of gaseous products is preferably done by steps, asdescribed above, where a continuous process is disclosed, since evenwith the efficient engineering and cooling of pre-vacuumed trap 17 withdry ice-isopropanol (−79° C.), the continuous flow of gases from reactor16 will result in bypassing 108 of 20-60% of Pt(PF₃)₄ in PF₃ trap 20leading to an additional steps (not shown) to recover all Pt(PF₃)₄ fromPF₃ trap 20. The additional steps may include warming up trap 20 abovethe boiling point of PF₃ (−102° C.), commonly to −79° C. (dry icecooling) and capture all PF₃ in a first separate trap (not shown) cooledwith liquid nitrogen. After all PF₃ is captured, trap 20 is warmed up toroom temperature and Pt(PF₃)₄ is captured in a second separate trap (notshown). The captured PF₃ in the first separate trap may be recycled toPF₃ 13 through line 110 for synthesize in reactor 16. Pre-vacuumed trap17, Pt(PF₃)₄trap 18 and PF₃ trap 20 and all connecting lines arefabricated from or made of metal, where the metal material is preferablycarbon steel, stainless steel and stainless steel alloy. In someembodiments, pre-vacuumed trap 17, Pt(PF₃)₄ trap 18 and PF₃ trap 20 andall connecting lines are made of stainless steel. All traps may have apassivated or electro-polished inner surface.

Pt(PF₃)₄ is separated from PF₃ by fractional distillation under air andmoisture free conditions. After collection of volatile species,pre-vacuumed trap 17 is warmed to a temperature ranging from −20 to −90°C., preferably from −60 to −80° C. and PF₃ is distilled in PF₃ trap 20maintained in a temperature ranging from −160 to −196° C. PF₃ in PF₃trap 20 may be stored, moved to a different location or recycled as PF₃13 for next synthesis.

Pt(PF₃)₄ contaminated with the solvent, reaction byproducts such assolid copper chlorides is remaining in pre-vacuumed trap 17 after PF₃uptake. Pt(PF₃)₄ in pre-vacuumed trap 17 has purity 90-99% and contain0.1-5% of PF₃ and 0.1-10% of solvent and 0.1-1% of other impuritiespreferably being phosphorus oxofluorides and solid copper chlorides.Pt(PF₃)₄ and solvent, solids are separated if a mixture is kept in atemperature ranging from 10 to 40° C., preferably at room temperatureand a receiver is kept in a temperature ranging from −50 to −196° C.,while the apparatus and the receiver may be pre-vacuumed before thedistillation and the pressure during the distillation is 0.01 Torr to760 Tory, preferably from 0.1 Torr to 5 Torr. More specifically,Pt(PF₃)₄ collected in pre-vacuumed trap 17 is purified by distillationin Pt(PF₃)₄ trap 18. In one embodiment, pre-vacuumed trap 17 containingPt(PF₃)₄ after PF₃ uptake is warmed to 0 to 40° C., preferably to roomtemperature and Pt(PF₃)₄ is distilled in pre-vacuumed trap 17 at apressure from 0.01-50 Torr, preferably 0.1-2 Torr, while Pt(PF₃)₄ trap18 kept in a temperature ranging from −15 to −196° C.

Pt(PF₃)₄ collected in Pt(PF₃)₄ trap 18 has a purity of 70-99.9% w/w,preferably 80-99.9% w/w, more preferably 90-99.9% w/w, even morepreferably 95-99.9% w/w, even more preferably 99.0-99.99% w/w afterpurification. Preferably, Pt(PF₃)₄ collected has a purity of99.50-99.99% w/w and contains 0-0.5% of PF₃, 0.01-0.5% of otherimpurities, such as phosphorus oxofluorides, thermal decompositionproducts such as Pt₄(PF₃)₄ and 0-0.5% of residual solvent. Purity ofPt(PF₃)₄ determined by ¹H, ¹⁹F, ³¹P, ¹⁹⁵Pt NMR, FTIR, and Ramanspectroscopy.

The purified Pt(PF₃)₄ may have an impurity of from approximately 0 wt. %to approximately 0.1 wt. % of PF₃, preferably from approximately 0 wt. %to approximately 0.05 wt. % of PF₃. The purified Pt(PF₃)₄ may havebetween approximately 0 wt. % to approximately 1 wt. % of phosphorusfluorides and oxofluorides including PF₃, POF₃, (HO)POF₂, (HO)₂POF,preferably between approximately 0 wt. % to approximately 0.05 wt. %.The purified Pt(PF₃)₄ may have between 0 wt. % to approximately 0.1 wt.% platinum compounds other than Pt(PF₃)₄. Preferably, approximately 0wt. % to approximately 0.05 wt. % of platinum compounds other thanPt(PF₃)₄. The total concentration of Pt(Hal)₂, Pt₄(PF₃)₈,Pt(Hal)₂(PF₃)_(x) (Hal=F, Cl, Br or I, x=1, 2) in Pt(PF₃)₄ may be fromapproximately 0 wt. % to approximately 0.1 wt. %, preferably fromapproximately 0 wt. % to approximately 0.05 wt. % after purification.Furthermore, the purified Pt(PF₃)₄ may have between 0.1 ppmw to 1000ppmw of solvent utilized for synthesis, preferably from approximately 0ppmw to 200 ppmw of solvent, more preferably from 0 ppmw to 50 ppmw ofsolvent, even more preferably from 0 ppmw to 20 ppmw of solvent.Moreover, the purified Pt(PF₃)₄ may have from approximately 0 ppmw toapproximately 100 ppmw of hydrogen fluoride, from 0 ppmw toapproximately 50 ppmw of hydrogen chloride. In addition, the purifiedPt(PF₃)₄ may have between approximately 0 ppb to 10 ppm of trace metals,such as iron, nickel, manganese, cobalt, copper, etc. The residual PF₃is recycled for synthesis of Pt(PF₃)₄.

In some embodiments, in order to determine the amount of organiccompounds in Pt(PF₃)₄, the internal standard, such as Me₄Si, may beused. In some embodiments, the sample preparation may involve absorbingthe organic solvent with the proper adsorbent such as C₈ derivatizedsilica gel.

In some embodiments, Pt(PF₃)_(x) trap 18 may include two subsequenttraps, e.g., trap 18 a and trap 18 b (not shown) for distillations toachieve the desired purity of Pt(PF₃)₄. After purification, Pt(PF₃)₄ maybe stored in Pt(PF₃)₄ trap 18 prior to packaging in metal ampoule 19 forshipment, deposition or storage. Alternatively, Pt(PF₃)₄ may be storedin metal ampoule 19 after packaging 109. Metal ampoule 19 may be a metalcontainer/vessel that is made of made of a metal, such as stainlesssteel, carbon steel, and stainless steel 316 alloy. The inner surface ofmetal ampoule 19 may be passivated with PF₃ or electro-polished.

The moisture from the surface of metal Pt(PF₃)₄ trap 18, metal ampoule19 may be removed by heating under vacuum at approximately 100 to 170°C. before introducing Pt(PF₃)₄ into metal Pt(PF₃)₄ trap 18 and metalampoule 19. Alternatively, the moisture from the surface of metalPt(PF₃)₄ trap 18, metal ampoule 19 may be removed by passivating thetrap vessels with PF₃ before introducing Pt(PF₃)₄ into metal Pt(PF₃)₄trap 18 and metal ampoule 19.

The purified Pt(PF₃)₄ may be stored in metal Pt(PF₃)₄trap 18, metalampoule 19 in the temperature range −80 to 60° C., preferably from 10 to40° C., more preferably from 20 to 25° C. The disclosed methods includestoring Pt(PF₃)₄ in a metal container, such as a stainless steel, carbonsteel, and stainless steel 316 alloy container. The inner surface of themetal container may be passivated with PF₃ or electro-polished. Here thestainless-steel container may be a stainless steel single-endedminiature sample cylinder or an electro-polished stainless-steelminiature canister. In one exemplary embodiment, the purified Pt(PF₃)₄was stored in a stainless steel single-ended miniature sample cylinderat room temperature for 2 months without change of Pt(PF₃)₄ purity.Alternatively, the purified Pt(PF₃)₄ was stored in an electro-polishedstainless-steel miniature canister at room temperature for 2 monthswithout change of Pt(PF₃)₄ purity.

The disclosed methods may be represented by a step process through asoluble intermediate, Pt(Hal)₂(PF₃)_(x) (x=1, 2; Hal=F, Cl, Br or I), asshown in FIG. 2 a , a so-called solid-gas, Pt(Hal)₂-M-PF₃, synthesisprocess in solution. Here HAL is F, Cl, Br or I, preferably Hal is Cl; Mis metal (such as Cu), then a Pt(Hal)₂-M-PF₃ synthesis process becomes aPtCl₂—Cu—PF₃ synthesis process. The disclosed method produces Pt(PF₃)₄in a high yield (i.e., 70 to 99.9%) with a high purity (i.e., more than99%, preferably more than 99.99%) and allows storage and delivery of thehighly pure Pt(PF₃)₄ without degrading the purity. Using a hydrocarbonsolvent is advantageous of the disclosed solid-gas, PtCl₂—Cu—PF₃,reaction process, in which the solvent is capable of dissolving thereaction intermediate (e.g., a platinum complex PtCl₂(PF₃)₂) formed frominsoluble starting materials, solid platinum compound PtCl₂ and PF₃ gas,under proper reaction conditions, and does not react with Pt(PF₃)₄.Utilization of such solvent allows obtaining Pt(PF₃)₄ in a high yield,at a shorter time, under low PF₃ pressure. Due to the lower pressure ofPF₃ in the disclosed synthesized method of Pt(PF₃)₄, cooling the reactorto condense PF₃ is eliminated and reactors with lower pressure ratingcould be used. As a result, commonly available equipment and reactorscould be utilized for the disclosed synthesis method of Pt(PF₃)₄. Thisresults in a Pt(PF₃)₄ synthesis process that is scalable to largeindustrial scale, with limited required equipment complexity due to itslower pressure requirement. The reaction conditions here includereaction temperature, reaction pressure and so on.

With the disclosed synthesis methods, the problem of low, moderate andirreproducible yield in the solid-gas reactions as well as a highpressure of PF₃ required for synthesis of Pt(PF₃)₄ is solved by additionof the disclosed solvent in the PtCl₂—Cu—PF₃ reaction system. Additionof solvent allows a synthesis of Pt(PF₃)₄ under a low PF₃ pressure, in ashorter time, with the reproducible high yield (Table 1, Examples #1 to#4). The reason for improvement in the synthesis process is solubilityof PtCl₂(PF₃)₂ obtained in situ from PtCl₂ and PF₃ under the lowpressure reaction conditions. It is a common knowledge thatsolution-solid reactions are much more efficient than the reactionbetween two different solids and gas. The addition of the solvent makesthe solid-gas, PtCl₂—Cu—PF₃, reaction system change to a solution-solidreaction that is much more efficient. Although application of solvent insynthesis is a common practice, it is not obvious solution for the givenreaction systems due to applied reaction conditions, a high reactivityof PF₃ as well as rich platinum coordination and catalytic chemistry inthe organic solvents, and could even be argued against.

The addition of the solvent in the solid-gas Pt(Hal)₂-M-PF₃ synthesissystem solves the problems of the low, moderate and irreproducible yieldin the solid-gas reactions (see the comparative Example 1 below) and ahigh pressure of PF₃ (50-150 Atm) required for synthesis of Pt(PF₃)₄.The addition of the solvent allows a synthesis of Pt(PF₃)₄ under a lowPF₃ pressure, in a shorter time, with the reproducible high yield, seeExamples 2 to 4 that follow. The reason for the yield improvement issolubility of the reaction intermediate PtCl₂(PF3)₂ obtained in situfrom PtCl₂ and PF₃ under certain reaction conditions (FIG. 3 ). Oncemore, it is known that solution-solid reactions are much more efficientthan the reaction between two different solids and gas. In the Examples2 to 4 that follow, the addition of the solvent in the PtCl₂—Cu—PF₃synthesis system allowed synthesis of Pt(PF₃)₄ under a 10 to 50 psig ofPF₃ pressure, in a 5 to 6 hours with a reproducible high yield (also seeExample 1) because a solid-gas, PtCl₂—Cu—PF₃ synthesis system, becomes asolution-solid reaction. As a result, commonly available equipment andreactors could be utilized for the disclosed synthesis processes ofPt(PF₃)₄.

Suitable solvents should be “inert” toward starting compounds andintermediates and product Pt(PF₃)₄ and not react with the startingcompounds and the intermediates and the product Pt(PF₃)₄ under thereaction conditions. In other words, the suitable solvents should not becatalytically transformed by the starting compounds, intermediates andproduct Pt(PF₃)₄ under the reaction conditions and the solvent shouldnot transform starting compounds and products in to other compounds. Thesuitable solvent should only dissolve at least one intermediate in thereaction to get the solution-solid reaction, which is much moreefficient, reproducible and therefore scalable than the reaction betweentwo different solids and gas. The suitable solvents should be able todissolve at least one platinum containing reaction intermediate such asPt(Hal)₂(PF₃)_(x), wherein Hal=F, Cl, Br or I; x=1, 2, obtained in situfrom Pt(Hal)₂ and PF₃ under the reaction conditions.

The platinum precursor may form the soluble reaction intermediate in thesolvent under certain reaction conditions, otherwise addition of solventwill result in a lower yield of Pt(PF₃)₄ compared to the reactionwithout the solvent, see the Comparative Example 1 (b)), where the yieldof Pt(PF₃)₄ is 60% in a 5014-gas reaction and Example 7 (#9), where theyield of Pt(PF₃)₄ is 26% for the reaction in hexadecane under the samepressure and temperature. The disclosed platinum precursor Pt(Hal)₂(Hal=F, Cl, Br or I) are forming soluble intermediates and hence theyare suitable for the disclosed synthesis process.

The suitable solvents used herein may be selected from ether, arene oralkane solvents. The preferred boiling point (BP) of the solvent may bemore than 150° C., preferably more than 200° C. This is necessary for anefficient separation of the solvent and the product Pt(PF₃)₄ since thecalculated boiling point of Pt(PF₃)₄ is ˜77° C. calculated from theequation log P=10.34−2610/T (P in Torr, T in Kelvin) from “VaporPressure Measurements of Volatile Transition-Metal Complexes”, by R. D.Sanner, J. H. Satcher, Jr., Report (1989), UCRL-53937. For example,hexadecane (BP: 285° C., melting point (MP): 18° C. and vapor pressure(VP): 0.07 Torr at 20° C.), p-cymene (BP: 177° C., MP: −68° C. and VP: 1Torr at 20° C) and dihexyl ether (BP: 223° C., MP: −43° C. and VP: 0.05Torr at 20° C). , triethylene glycol dimethyl ether (BP: 216° C., MP:−45° C. and VP: 0.025 Torr at 20° C.), tetraethylene glycol dimethylether (BP: 275° C., MP: −30° C. and VP: 0.001 Torr at 20° C.) may besuitable for using as a solvent in the disclosed Pt(Hal)₂-M-PF₃synthesis system.

In one embodiment, the intermediate PtCl₂(PF₃)₂was isolated from thereaction of PtCl₂ and PF₃ in hexadecane, identity confirmed by analysis.PtCl₂(PF₃)₂ further reacted with copper and PF₃ under the conditionsdisclosed in #5 in Table 1 producing Pt(PF₃)₄.

Anhydrous solvents have to be applied for synthesis of Pt(PF₃)₄ becausePF₃, PtCl₂, PtCl₂(PF₃)_(x) (x=1, 2) and Pt(PF₃)₄ react with moisture.The reactions with moisture result in side products such as HCl, HF,and/or phosphorus oxofluorides, fluorophosphoric acids, whichcontaminate the product Pt(PF₃)₄. For example, HF may form SiF₄ whenPt(PF₃)₄ is placed in any vessels made from glass. To prevent theformation of contaminants, the commercially available solvent may bedried by contacting with the drying agent.

FIG. 2 a is a flowchart of the disclosed Pt(Hal)₂-M-PF₃ synthesisprocess for synthesis of Pt(PF₃)₄ starting with Pt(Hal)₂ (Hal=F, Cl, Bror I). Starting materials include Pt(Hal)₂ (Hal=F, Cl, Br or I) andmetal powder (M) and PF₃. In a reaction temperature ranging from 20-180°C., Pt(Hal)₂ (Hal=F, Cl, Br or I) and the metal powder may not besoluble. For example, PtCl₂ is not soluble at a reaction temperatureranging from 20-180° C. First, at step 202, a suspension of the startingmaterials Pt(Hal)₂ (Hal=F, Cl, Br or I) and a metal powder is formed inan anhydrous solvent by dispersing Pt(Hal)₂ (Hal=F, Cl, Br or I) and themetal powder to the anhydrous solvent. Afterward, excess PF₃ gas isintroduced into the suspension of Pt(Hal)₂ (Hal=F, Cl, Br or I) and themetal powder. Here, preferably, Hal=Cl, then Pt(Hal)₂ is PtCl₂.Preferably, the metal powder is a Cu powder.

Pt(Hal)₂ (Hal=F, Cl, Br or I) is anhydrous and suspended in theanhydrous solvent. A solvent is dried by a drying agent to form theanhydrous solvent that is used to mix with the starting materialsanhydrous Pt(Hal)₂ and metal powder. The solvent or anhydrous solventmay be a hydrocarbon solvent, such as an oxyhydrocarbon solvent, havinga general formula (C_(n)H_(2n+1))₂O and H₃C(O(CH₂)₂)_(n)OCH₃ (n≥1), anarene solvent having a general formula (C_(n)H_(2n+1))_(x)C₆H_(6−x)(x≥1, n≥1) or an alkane solvent having a general formula C_(n)H_(2n+2)(n≥1). The anhydrous solvent suitable for using in the disclosed methodsmay be a dried alkane solvent selected from decane, di-, tri-, tetra,penta- and hexadecane, the like; a dried arene solvent selected fromxylene, mesithylene, cymene, pentylbenzene, diisopropylbenzene,diisobutylbenzene, or the like; a dried ether solvent selected fromdibutyl ether, dihexyl ether, dioctyl ether, dimethyl ether ofdiethylene glycol, triethylene glycol dimethyl ether, tetraethyleneglycol dimethyl ether or the like; or an arene solvent selected fromxylene, mesithylene, cymene, pentylbenzene, diisopropylbenzene,diisobutylbenzene or the like; or combinations thereof. The ethersolvent is preferably dibutyl ether, dihexyl ether, dioctyl ether,triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether.Th arene solvent is preferably xylene, mesithylene, cymene,pentylbenzene, diisopropylbenzene, diisobutylbenzene. The alkane solventis preferably di-, tri-, tetra, penta- and hexadecane as well as amixture of alkanes known as a mineral oil. The anhydrous solvent used inthe disclosed methods may be xylene or hexadecane.

In some embodiments, the solvent or anhydrous solvent may be xylene orhexadecane. The drying agent may be 3 Å or 4 Å molecular sieves.Pt(Hal)₂ (Hal=F, Cl, Br or I), the metal powder and excess PF₃ in theanhydrous solvent may form a soluble reaction intermediatePt(Hal)₂(PF₃)_(x) (x=1, 2; Hal=F, Cl, Br or I) at step 204. The solventor the anhydrous solvent used herein has to be able to dissolvePt(Hal)₂(PF₃)_(x) (x=1, 2; Hal=F, Cl, Br or I), a soluble reactionintermediate. Here excess PF₃ may be added into the suspension ofPt(Hal)₂ (Hal=F, Cl, Br or I) and the metal powder. Thus, the solublereaction intermediate Pt(Hal)₂(PF₃)_(x) (x=1, 2; Hal=F, Cl, Br or I) maybe formed from Pt(Hal)₂ (Hal=F, Cl, Br or I) and excess PF₃ at atemperature, for example, between 80° C. to 130° C. and a low pressure,for example, between 20 psig to 300 psig. Pt(Hal)₂ (Hal=F, Cl, Br or I)reacts with excess PF₃ may produce a solution of the reactionintermediate Pt(Hal)₂(PF3)_(x) (x=1, 2; Hal=F, Cl, Br or I) in theanhydrous solvent since the solvent is selected to be able to dissolvethe intermediate Pt(Hal)₂(PF₃)_(x) (x=1, 2; Hal=F, Cl, Br or I). At step206, the solution of the reaction intermediate Pt(Hal)₂(PF₃)_(x) (x=1,2: Hal=F, Cl, Br or I) may react with the metal powder and PF₃ gas(e.g., when Hal=Cl, the metal powder is a Cu powder,PtCl₂(PF₃)₂+2Cu+3PF₃=2CuCl+Pt(PF₃)₄) to form Pt(PF₃)₄. At this step,excess of PF₃ is used. Then, at step 208, the produced Pt(PF₃)₄ isseparated and purified from unreacted starting materials, the solventand reaction byproducts such as copper halides (e.g., CuCl, CuCl₂) andtheir complexes with PF₃. The separation and purification steps may beperformed in a pre-vacuumed trap and/or a metal trap to remove residualPF₃ and the solvent and the reaction byproducts, as shown in FIG. 1 .The residual PF₃ may be recycled to be used as the starting material.The metal traps may be made of a metal, such as stainless steel, carbonsteel, and stainless steel 316 alloy. The purified product Pt(PF₃)₄ isthen stored in a metal ampoule or vessel or container at step 210. Thestorage metal ampoule or vessel or container may be made of a metal,such as stainless steel, carbon steel, and stainless steel 316 alloy.Alternatively, the storage ampoule or vessel or container may be made ofplastic. The inner surface of the ampoule or vessel or container may bepassivated with PF₃ or electro-polished.

In the disclosed methods, the anhydrous solvents have to be applied forsynthesis of Pt(PF₃)₄ because PF₃, PtCl₂, PtCl₂(PF₃)_(x) (x=1, 2) andPt(PF₃)₄ react with moisture. To prevent the formation of contaminants,the commercially available solvent may be dried by contacting with thedrying agent selected from 3 Å or 4 Å molecular sieves or activatedalumina. Solvent drying processes may be achieved by contacting thesolvent and the drying agent, which may be achieved in a static processor in a flow process. Before the drying step, the commercially availablesolvent may be degassed by passing an inert gas or by applyingvacuum-inert gas cycles, where the vacuum is in the range 0.1 Torr to100 Torr, preferably 0.5-10 Torr and the inert gas is selected from N₂,Ar or He containing less than 1 ppm of oxygen and moisture.Alternatively, the commercially available solvent dried with the dryingagent without degassing.

The disclosed synthesis methods provide practical/scalable synthesismethods of Pt(PF₃)₄, through tuning and optimizing reaction conditionsthat favor the product Pt(PF₃)₄ in a high yield and minimize effects ofside reactions. The disclosed synthesis methods may be carried out in astandard high pressure reactor, e.g., reactors from Parr InstrumentCompany Series 4520, 4530, 4540, 4540 rated from 1900 to 5000 psig; inpressure rated glass reactors, e.g., in Series 5100 Glass Reactors fromParr Instrument Company rated up to 150 psig; or in lab and pilotpressure reactors from Büchiglas and equipped with standard stirrers andheaters.

In some embodiments, the disclosed synthesis methods for synthesis,purification and storage of Pt(PF₃)₄ may comprise the following steps:

a) drying a solvent;

b) dispersing a platinum compound having a general formula Pt(Hal)₂(Hal=Cl, Br, I), such as PtCl₂, and a metallic powder having certainparticle sizes such as a metallic copper powder, into the dried oranhydrite solvent in a flow reactor, forming a mixture or a suspensionof Pt(Hal)₂ (Hal=Cl, Br, I) and the metallic copper powder;

c) adding excess amount of PF₃ to the mixture or the suspension;

d) stirring a reaction mixture formed in the step c) under a requiredtemperature and a required PF₃ pressure (i.e., low PF₃ pressure) thatlead to the following reactions and products:

-   -   a. formation of PtCl₂(PF₃)_(x) (x=1, 2);    -   b. solution of PtCl₂(PF₃)_(x) in the dried solvent; and    -   c. reaction of PtCl₂(PF₃)_(x) and PF₃ with the metallic copper        powder to form a product Pt(PF₃)₄;

e) purifying the product Pt(PF₃)₄ through distilling volatile speciesfrom the reaction mixture into a separate trap that allows:

-   -   i. separating unreacted starting material(s), byproducts,        solvent; and    -   ii. separating of the product Pt(PF₃)₄ from unreacted PF₃.

f) purifying the crude Pt(PF₃)₄ by distillation;

g) recycling the unreacted PF₃ to the step c); and

h) storing the purified product Pt(PF₃)₄ in a metal ampoule or containermade of a metal, such as stainless steel, carbon steel, and stainlesssteel 316 alloy and the inner surface of the metal ampoule or containeris passivated by PF₃ or electro-polished.

Alternatively, the disclosed methods for synthesizing Pt(PF₃)₄ with aplatinum compound Pt(Hal)₂, wherein Hal=F, Cl, Br or I comprise thefollowing steps:

-   -   dispersing the platinum compound Pt(Hal)₂, wherein Hal=F, Cl, Br        or I into an anhydrous solvent forming a suspension of Pt(Hal)2;    -   introducing excess amount of PF₃ into the suspension of        Pt(Hal)₂;    -   forming a solution of the platinum compound Pt(Hal)₂(PF₃)_(x) in        the anhydrous solvent therefrom through a reaction of PF₃ and        Pt(Hal)₂;    -   adding a metal powder having certain particle sizes and        additional excess amount of PF₃ into the Pt(Hal)₂(PF₃)_(x)        solution; and    -   forming Pt(PF₃)₄ through a reaction between Pt(Hal)₂(PF₃)_(x),        PF₃ and the metal powder under a reaction condition.

In this case, Pt(Hal)₂(PF₃)_(x) is a reaction intermediate synthesizedby excess amount of PF₃ with the suspension of Pt(Hal)₂ in an anhydroussolvent. Once again, using solvent for the synthesis of Pt(PF₃)₄ appearsnovel. To our best knowledge, Pt(PF₃)₄ was never synthesized from anyplatinum compound including the reaction intermediate Pt(Hal)₂(PF₃)_(x)(Hal=F, Cl, Br or I; x=1, 2) in a solvent.

Alternatively, the disclosed methods for synthesizing Pt(PF₃)₄ with aplatinum compound Pt(Hal)₂, wherein Hal=F, Cl, Br or I, comprise thefollowing steps:

-   -   providing a metal powder having certain particle sizes;    -   providing PF₃ gas;    -   synthesizing Pt(PF₃)₄ from the metal powder, PF₃ and the        platinum compound Pt(Hal)₂, wherein Hal=F, Cl, Br or I, in an        anhydrous solvent capable of dissolving at least one platinum        containing reaction intermediate Pt(Hal)₂(PF₃)_(x) (Hal=F, Cl,        Br or I; x=1, 2), which is formed from the platinum precursor        Pt(Hal)₂ and PF₃ under reaction conditions, such as a low        pressure from 20 psig to 300 psig and a temperature ranging from        80° C. to 130° C.; and    -   purifying and storing Pt(PF₃)₄ at an air and moisture free        condition in apparatus and ampoules fabricated from metal or        plastic.

Alternatively, the disclosed method for synthesis of Pt(PF₃)₄ with aplatinum compound Pt(Hal)₂, wherein Hal=F, Cl, Br or I comprises thefollowing steps:

-   -   a) drying a solvent with a drying agent to form an anhydrous        solvent;    -   b) adding a metal powder having certain particle sizes, a        platinum compound having a general formula Pt(Hal)₂, wherein        Hal=F, Cl, Br or I, and excess amount of PF₃ to the anhydrous        solvent to form Pt(Hal)₂(PF₃)_(x), where x=1, 2, wherein the        anhydrous solvent is capable of dissolving Pt(Hal)₂(PF₃)_(x);    -   c) synthesizing Pt(PF₃)₄ by the reaction of the metal powder,        PF₃, and Pt(Hal)₂(PF₃)_(x) in the anhydrous solvent; and    -   d) purifying the synthesized Pt(PF₃)₄ and storing the purified        Pt(PF₃)₄ under air and moisture free conditions in apparatus and        ampoules fabricated from metal or plastic, such as stainless        steel or plastic.

Here the plastic may be selected from polyethylene, polypropylene,styrene, teflon, polytetrafluoroethylene (PTFE), perfluoroalkoxy alkane(PFA).

As describe above, the reaction intermediates Pt(Hal)₂(PF₃)_(x) (Hal=F,Cl, Br or I; x=1, 2) are soluble in hydrocarbon solvents and can beisolated and purified. Synthesis of Pt(PF₃)₄ may be start with theplatinum compound Pt(Hal)₂(PF₃)_(x) (Hal=F, Cl, Br or I; x=1, 2). FIG. 2b is a flowchart of an exemplary process of synthesizing Pt(PF₃)₄starting with Pt(Hal)₂(PF₃)_(x) (x=1, 2; Hal=F, Cl, Br or I). As shown,at step 302, a Pt(Hal)₂(PF₃)_(x) (Hal=F, Cl, Br or I; x=1, 2) solutionis formed by dissolving Pt(Hal)₂(PF₃)_(x) (Hal=F, Cl, Br or I; x=1, 2)into an anhydrate solvent. Preferably, Hal is Cl, Pt(Hal)₂(PF₃)_(x) isPtCl₂(PF)_(x). Then at step 304, a metal powder having certain particlesizes is introduced into the Pt(Hal)₂(PF₃)_(x) (Hal=F, Cl, Br or I; x=1,2) solution and forms a suspension. Preferably, the metal powder is a Cupowder having certain particle sizes. Afterwards, excess PF₃ gas isintroduced into the suspension at step 306. Then, Pt(PF₃)₄ is formedunder low pressure by reacting Pt(Hal)₂(PF₃)_(x) (x=1, 2; Hal=F, Cl, Bror I) with the metal powder and PF₃ at step 308. At this step, excess ofPF₃ is used. Then, at step 310, the produced Pt(PF₃)₄ is separated andpurified from unreacted starting materials, the solvent and reactionbyproducts such as copper halides (e.g., CuCl, CuCl₂) and theircomplexes with PF₃. The separation and purification steps may beperformed in a pre-vacuumed trap and/or a metal trap to remove residualPF₃ and the solvent and the reaction byproducts, as shown in FIG. 1 .The residual PF₃ may be recycled to be used as the starting material.The metal traps may be made of a metal, such as stainless steel, carbonsteel, and stainless steel 316 alloy. The purified product Pt(PF₃)₄ isthen stored in a metal ampoule or vessel or container at step 312. Thestorage metal ampoule or vessel or container may be made of a metal,such as stainless steel, carbon steel, and stainless steel 316 alloy.Alternatively, the storage ampoule or vessel or container may be made ofplastic. The inner surface of the ampoule or vessel or container may bepassivated with PF₃ or electro-polished.

The disclosed methods for synthesizing Pt(PF₃)₄ with a platinum compoundPt(Hal)₂(PF₃)_(x), wherein Hal=F, Cl, Br or I; x=1, 2, comprise thefollowing steps:

-   -   dissolving Pt(Hal)₂(PF₃)_(x) (Hal=F, Cl, Br or I; x=1, 2) in an        anhydrous solvent forming a Pt(Hal)₂(PF₃)_(x) solution;    -   adding a metal powder having certain particle sizes and excess        amount of PF₃ into the Pt(Hal)₂(PF₃)_(x) solution; and    -   forming Pt(PF₃)₄ through a reaction between Pt(Hal)₂(PF₃)_(x),        PF₃ and metal powder under a reaction condition of a low        pressure ranging from 20 psig to 300 psig and a temperature        ranging from 80° C. to 130° C.

Alternatively, the disclosed methods for synthesizing Pt(PF₃)₄ with aplatinum compound Pt(Hal)₂(PF₃)_(x), wherein Hal=F, Cl, Br or I; x=1, 2,comprise the following steps:

a) drying a solvent with a drying agent to form an anhydrous solvent;

b) adding the platinum compound Pt(Hal)₂(PF₃)_(x), wherein Hal=F, Cl, Bror I; x=1, 2, a metal powder having certain particle sizes and excessamount of PF₃ to the anhydrous solvent to synthesize Pt(PF₃)₄, whereinthe anhydrous solvent is capable of dissolving Pt(Hal)₂(PF₃)_(x); and

c) purifying the synthesized Pt(PF₃)₄ and storing the purified Pt(PF₃)₄under air and moisture free conditions in apparatus and ampoulesfabricated from metal or plastic, such as stainless steel.

Here the plastic may be selected from polyethylene, polypropylene,styrene, teflon, polytetrafluoroethylene (PTFE), perfluoroalkoxy alkane(PFA). The metal may be selected from selected from carbon steel,stainless steel, or stainless steel 316 alloy. The metal powder may be aCu, Zn or Al powder, or the like.

The disclosed also include the purity of the product Pt(PF₃)₄ andstorage vessels for the product Pt(PF₃)₄. The product Pt(PF₃)₄ may bestored in stainless steel and electro-polished stainless steel vesselsat room temperature without changing of purity. The disclosed methodsfor synthesis of Pt(PF₃)₄ further comprise the steps of purifying thesynthesized Pt(PF₃)₄:

-   -   distilling the synthesized Pt(PF₃)₄ in a metal trap to remove        the solvent and by-products, forming a by-product removal        Pt(PF₃)₄;    -   distilling the by-product removal Pt(PF₃)₄ in a metal vessel to        remove the solvent and residual PF₃, forming a purified        Pt(PF₃)₄; and    -   optionally, recycling the residual PF₃ for synthesizing        Pt(PF₃)₄.

The disclosed methods for synthesizing Pt(PF₃)₄ further comprise thesteps of storing the purified Pt(PF₃)₄:

-   -   storing the purified Pt(PF₃)₄ in a metal (e.g., stainless steel)        vessel or an inner surface passivated or electro-polished metal        (e.g., stainless steel) vessel at room temperature.

Here, the purity of the purified Pt(PF₃)₄ stored in the metal vessels oran inner surface passivated or electro-polished metal vessels may notchange and remains constant. The vessel fabricated from carbon steel,stainless steel, and stainless steel 316 alloy. The metal vessel mayhave electro-polished inner surface. Alternatively, Pt(PF₃)₄ may bestored in a plastic vessel. The plastic material may be polyethylene,polypropylene, styrene, teflon, polytetrafluoroethylene (PTFE),perfluoroalkoxy alkane (PFA).

The metal powder used in the disclosed methods consists of a metalhaving an electrode potential lower than that of platinum, notinteracting with PF₃ and not forming complexes with PF₃ under thereaction conditions and having a proper particle size range allowing itto stay in a powder form during the reaction process.

The metal powder preferably is a copper, zinc, aluminum powder, or thelike. Any metal and its halide not interacting with PF₃ and not formingcomplexes with PF₃ under the reaction conditions and having theelectrode potential lower than that of platinum (+1.2) may be usedherein. For example, Cu (+0.34), Pb (−0.13), Sn (−0.14), Cd (−0.40), Zn(−0.76) and their halides do not interact with PF₃ under the reactionconditions and do not form complexes with PF₃, which may be used as themetal powder.

EXAMPLES

The following non-limiting examples are provided to further illustrateembodiments of the invention. However, the examples are not intended tobe all-inclusive and are not intended to limit the scope of theinventions described herein.

Experimental Procedures

Reaction mixtures, starting materials, solvents and products may beanalyzed by any suitable means, such as by gas chromatography, NMR,Raman, FTIR spectroscopy using part of the stream or aliquots. Allmeasurements were performed for samples in the closed containers,suitable tubes, or ampoules without any contact with atmospherecontaining oxygen and moisture. Liquid nitrogen, nitrogen gas of highpurity with less than 0.1 ppm of O₂ and water.

Reagents: Potassium Hexachloroplatinate (IV) (K₂PtCl₆, Pt Assay40.1±0.7%, CAS: 16921-30-5) was from Colonial Metals, Inc.; Platinum(II) chloride (PtCl₂, Pt Assay 73.3±1.0%, CAS: 10025-65-7) was fromColonial Metals, Inc. Three types of copper powder, one was (99.999%)100 mesh (100 mesh=149 μm) from Strem Chemicals Inc.; another one was<425 μm, 99.5% from Sigma-Aldrich; another one was <45 μm, 99.99% fromSigma-Aldrich. Phosphorus (III) fluoride (PF₃, CAS: 7783-55-3) was fromAdvance Research Chemicals, Inc. Molecular sieves, 3 Å, beads, 4-8 mesh(Sigma-Aldrich), were regenerated either in dry nitrogen stream attemperatures 300-350° C. or under vacuum at temperatures 300-350° C. andoperated under nitrogen atmosphere with less than 0.5 ppm of O₂ andmoisture after regeneration. Solvents xylenes and hexadecane were fromSigma-Aldrich degassed and dried over 3 Å molecular sieves. The reactorwas loaded with platinum compound and copper powders under nitrogenatmosphere with less than 0.5 ppm of O₂ and water.

Example 1. Synthesis of Pt(PF₃)₄ in High Pressure Reactor withHexadecane Solvent

Referring to Table 1 below, amounts of PtCl₂, Cu, hexadecane are loadedin a reactor from Parr Instrument Company (Series 4540, 600 mL rated for5000 psig) in a glove box. The reactor transferred and connected to thevacuum line, vacuumed below 0.3 Torr and the required amount of PF₃introduced in the reactor below −79° C. (#1-3) or at room temperature(#6). Then the reactor warmed to room temperature, stirring started, andthen the temperature in reactor increased to 105° C. and the reactionmixture stirred under PF₃ pressure. In reaction #6, PF₃ is added in thereactor by portions during the reaction to maintain pressure in therange 100-200 psig. The pressure decrease observed in all reactionsduring the first 6 hours at 105° C. and then the pressure stabilizedindicating that the reaction may take approximately 6 hours. Thepressure in reactor monitored during several more hours, then thereactor content cooled to 35-45° C. and the portion of gases (about25-35%) directed in pre vacuumed trap (0.44 L, material stainless steel)cooled with the dry ice-isopropanol mixture. In reaction #6, allpressure released in the trap. The reactor closed, trap kept for about10 min and then the non-condensable gas directed in the second trapcooled with liquid nitrogen (6 L, material Aluminum). Transfer lines andvalves were warmed if cooled below 0° C. with the passing gas. Aftercondensation of PF₃ portion in 6 L Al trap, vacuum applied to 6 L Altrap to get the pressure in trap below 1 Torr. Operation repeated untilall PF₃ and Pt(PF₃)₄ were stripped from the reactor and collected in twodifferent traps. Then the trap with Pt(PF₃)₄ was reconnected to aseparate pre-vacuumed vessel (0.4 L, electropolished stainless steel).The parent trap with Pt(PF₃)₄ warmed to room temperature, while areceiving vessel cooled with liquid nitrogen and all Pt(PF₃)₄ distilledin the receiving vessel under a static vacuum. After distillation, thereceiving vessel warmed to room temperature and the residual PF₃released through the scrubber. Yield of Pt(PF₃)₄ is in Table 1 below.

TABLE 1 PF₃ Yield of PtCl₂ (psig) at Pt(PF₃)₄ # (g) Solvent (mL) 105° C.(%, g) Reactor 1 25.7 Hexadecane 100 2250-2350 93% (49.3 g) SS Steel 240.3 Hexadecane 150 2150-2350 88% (73.5 g) SS Steel 3 51.0 Hexadecane129 2300-2500 86% (90.0 g) SS Steel 4 8.75 Hexadecane 40 20-50 79% (14.3g) Glass 5 2.19 Xylene 18.5 20-40 95% (4.3 g)  Glass  6* 50 Hexadecane200 100-200 90% (94 g)   SS Steel *Reaction 6 is prophetic. SS Steelreactor = high pressure reactor from Parr instrument Company (Series4540, 600 mL). Glass reactor = 150 mL HW Pressure Glass Vessel fromChemglass Life Sciences, part number CG-1880-31. The glass vessel isequipped with the thermocouple and pressure gauge.

Purity of Pt(PF₃)₄ is more than 99% in all experiments according to ¹H,¹⁹F NMR. For example, reaction #1, ¹⁹F NMR of neat product (σ CFCl₃,ppm): −11.5 (m, J(P-F)=1302 Hz, 99.63%, Pt(PF₃)₄), −34.4 (d, J(P-F)=1402Hz, 0.05%, PF₃), −81.58 (0.19%, fluorophosphoric acid, not assigned),−92.4 (d, J(P-F)=2035 Hz, 0.12%, POF₃). ¹H NMR of neat product (σ SiMe₄,ppm): 0.90 and 1.32 (hexadecane), 13.1 (s, fluorophosphoric acid).Determination of hexadecane by ¹H NMR. Taken 0.18 g of purified productfrom reaction #1 and mixed with in 0.77 g of C₆D₆ containing 0.03% (0.23mg, 0.0026 mmol of SiMe₄). ¹H NMR of solution (σ SiMe₄, ppm): 0.00 (s,97.7 mol. %, SiMe₄), 1.32 (2.3 mol. %, hexadecane), 7.16 (s,fluorophosphoric acid, relative intensity not measured since C₆C₆ notdried from moisture). If to recalculate mol % to wt. %, and count thatsolution contains 0.23 mg TMS, then the total amount of hexadecane inPt(PF₃)₄ sample is 0.014 mg corresponding to 79 ppm in Pt(PF₃)₄ fromreaction #1.

Additional trap to trap distillation afford Pt(PF₃)₄ with purity 99.79%,¹⁹F NMR of neat sample measured in glass ampoule (σ CFCl₃, ppm): −11.5(m, J(P-F)=1302 Hz, 99.79%, Pt(PF₃)₄), −88.20 (d, J(P-F)=975 Hz, 0.19%,(HO)POF₂), −92.4 (d, J(P-F)=2035 Hz, 0.01%, POF₃) −166.1 (s, 0.02%,SiF₄). ¹H NMR of neat sample (σ SiMe₄, ppm): 0.90 and 1.32 (hexadecane,rel. int. 28%), 12.94 (s, (HO)POF₂, rel. int. 72%). The resonances ofhexadecane were below the limit of detection for solution of 0.07 g ofsample in 0.78 g of C₆D₈ containing 0.03% of SiMe₄. Hence the totalamount of hexadecane is less than 80 ppm. FTIR. [liquid Pt(PF₃)₄ onGolden Gate™ probe, resolution 4 cm⁻¹]: 882, 827, 496 cm⁻¹.

Example 2. Synthesis of Pt(PF₃)₄ with Isolation of PtCl₂(PF₃)₂ andHexadecane Solvent

a) Synthesis of PtCl₂(PF₃)_(x) (x=1, 2) in Hexadecane.

PtCl₂ (1.9 g, 7.1 mmol), hexadecane (15.8 g, 20.4 mL) loaded in the 150mL pressure glass ampoule (Chemglass Life Sciences, part numberCG-1880-31) equipped with a stirring bar, thermocouple, pressure gauge.The ampoule connected to a vacuum line and cylinder with PF₃. Theampoule with the starting materials vacuumed to around 0.2 Torr toremove nitrogen, then 35 psig of PF₃ added and the suspension heatedunder stirring. The content stirred for 4 hours in the temperature range100-120° C. under 20-35 psig of PF₃, where PF₃ added by portions whenthe pressure was approaching to 20 psig. During the reaction, initiallyinsoluble in hexadecane PtCl₂ fully reacted with PF₃ and formed solublein hexadecane compounds, which partially sublimed on the colder parts ofapparatus as colorless crystals. After 4 hours, the heating stopped,reaction mixture cooled to room temperature, PF₃ condensed back in thecylinder and a portion of crystals separated from solution and analyzed;the portion of supernatant hexadecane solution also analyzed by ¹⁹F NMR.¹⁹F NMR of crystals dissolved in pure, anhydrous hexadecane (σ CFCl₃,ppm): −36.4 (m, J(Pt-F)=628 Hz, J(P-F)=1320 Hz, PtCl₂(PF₃)₂). ¹⁹F NMR ofhexadecane supernatant solution (σ CFCl₃, ppm): −32.5 (d, J(P-F)=1405Hz, PF₃), −36.4 (m, J(Pt-F)=622 Hz, J(P-F)=1318 Hz, PtCl₂(PF₃)₂). FTIRof crystals (neat solid on Golden Gate™ probe, resolution 4 cm⁻¹): 417(sh, w), 447 (sh, w), 461 (m), 483 (s), 507 (5), 518 (s), 531 (m), 551(5), 901 (vs), 907 (sh), 933 (vs), 961 (s), 969 (w), 974 (m), 985 (w)DSC of crystals: 19.0° C. (phase transition), 72.5° C. (phasetransition), 118.3° C. (melting point).

b) Synthesis of Pt(PF₃)₄ from PtCl₂(PF₃)_(x) (x=1, 2) in Hexadecane.

The colorless crystals from a) placed in a supernatant hexane solution,copper added (2.22 g, 34.9 mmol) and the ampoule (150 mL HW PressureGlass Vessel) connected to a vacuum line and a cylinder with PF₃. Theampoule with the starting materials briefly vacuumed to about 2 Torr toremove nitrogen, then 40 psig of PF₃ added and the suspension heated inthe temperature range 100-130° C. under stirring for 4 hours. Thereaction is under 20-40 psig of PF₃, where PF₃ added by portions whenthe pressure was approaching to 20 psig. After 4 hours heating stopped,the reaction mixture cooled to 35° C. and Pt(PF₃)₄, PF₃, some solventcondensed in the trap (made from stainless steel) cooled with liquidnitrogen under the static vacuum. Pt(PF₃)₄ purified from PF₃ andresidual hexadecane by trap to trap distillation. Yield of Pt(PF₃)₄ is1.25 g (32%, low yield since part of PtCl₂(PF₃)₂ and supernatantsolution used for analyses in a)). ¹⁹F NMR of neat product Pt(PF₃)₄ (σCFCl₃, ppm): −11.5 (m, J(P-F)=1301 Hz, Pt(PF₃)₄). ¹H NMR of neat product(σ SiMe₄, ppm): 0.23 (t, J=6.1 Hz, 71.7 mol. %, Me₂SiF₂), 0.90 and 1.32(28.3 mol. %, hexadecane).

Example 3. Synthesis of Pt(PF₃)₄ in Glass Ampoule with HexadecaneSolvent

PtCl₂ (8.75 g, 32.9 mmol), Cu (18.25 g, 287.2 mmol), hexadecane (30.95g, 40 mL) loaded in an ampoule (150 mL HW Pressure Glass Vessel fromChemglass Life Sciences, part number CG-1880-31) equipped with astirring bar, thermocouple, pressure gauge. The ampoule connected to avacuum line and cylinder with PF₃. The ampoule with the startingmaterials vacuumed to about 0.2 Torr to remove nitrogen, then 40 psig ofPF₃ added and the content heated under stirring. The content stirred for5.5 hours in the temperature range 110-120° C. under 20-50 psig of PF₃,where PF₃ added by portions when the pressure was approaching to 20psig. During the reaction, crystals of PtCl₂(PF₃)₂ formed and thenconsumed and at the end of reaction the reaction mixture contained twonon-miscible liquids. After 5 hours 30 min heating stopped, the reactionmixture cooled to 41° C. and Pt(PF₃)₄, PF₃, some solvent condensed inthe trap (made from stainless steel) cooled with liquid nitrogen underthe static vacuum. Pt(PF₃)₄ purified from PF₃ and residual hexadecane bytrap to trap distillation. Yield of Pt(PF₃)₄ is 79% (14.2 g). ¹⁹F NMR ofneat sample (σ CFCl₃, ppm): −11.5 (m, J(P-F)=1301 Hz, 99.40%, Pt(PF₃)₄),−34.4 (d, J(P-F)=1402 Hz, 0.36%, PF₃), −92.4 (d, J(P-F)=2035 Hz, 0.23%,POF₃), −166.0 (s, 0.007%, SiF₄). ¹H NMR of neat sample (σ SiMe₄, ppm):0.23 (t, J=6.1 Hz, 67.4 mol. %, Me₂SiF₂), 0.90 and 1.32 (6.9 mol. %,hexadecane), 1.45 (d, J=6.1 Hz, 25.8 mol. %, P(O^(i)Pr)₃). Determinationof the organic content by ¹H NMR. The intensities of the resonances oforganic compounds were below the limit of detection for solution of 0.09g of Pt(PF₃)₄ sample dissolved in 0.76 g of C₆D₆ containing 0.03% (0.228mg, 0.0026 mmol of SiMe₄). Hence the total amount of organic compoundsis less than 80 ppm in Pt(PF₃)₄.

Example 4. Synthesis of Pt(PF₃)₄ in Glass Ampoule Applying XyleneSolvent

PtCl₂ (2.19 g, 8.2 mmol), Cu (4.69 g, 73.8 mmol), xylenes (16.1 g)loaded in a 150 mL pressure glass ampoule (Chemglass Life Sciences, partnumber CG-1880-31) equipped with a stirring bar, thermocouple, pressuregauge. The ampoule connected to a vacuum line and a cylinder with PF₃.The ampoule with the starting materials briefly vacuumed to around 3Torr to remove nitrogen, then 40 psig of PF₃ added and the contentheated under stirring. The content stirred for 4.5 hours in thetemperature range 100-120° C. under 20-40 psig of PF₃, where PF₃ addedby portions when the pressure was approaching to 20 psig. During thereaction, crystals of PtCl₂(PF₃)₂ formed and then consumed and at theend of reaction the reaction mixture contained two non-miscible liquids.After 4 hours 30 min heating stopped, the reaction mixture cooled to 38°C. and Pt(PF₃)₄, PF₃, some solvent condensed in the trap (made fromstainless steel) cooled with liquid nitrogen under the static vacuum.Pt(PF₃)₄ purified from PF₃ and residual solvent xylene by trap to trapdistillation. Yield of Pt(PF₃)₄ is 95% (4.3 g). ¹⁹F NMR of neat sample(σ CFCl₃, ppm): −11.5 (m, J(P-F)=1301 Hz, 99.58%, Pt(PF₃)₄), −34.4 (d,J(P-F)=1402 Hz, 0.39%, PF₃), −92.4 (d, J(P-F)=2035 Hz, 0.03%, POF₃),−166.0 (s, 0.01%, SiF₄). % are from integration. ¹H NMR of neat sample(σ SiMe₄, ppm): 0.12 (t, J=6.1 Hz, 0.7 mol. %, Me₂SiF₂), 1.11 (t) and2.56 (q) (18.8 mol %, Et-C₆H₅), 2.05 (s) and 2.14 (s) (79.4 mol. %,xylenes), 6.97 (m, aromatic protons), 12.46 (br, 1.0 mol. %,fluorophosphoric acid). Determination of the residual solvent by ¹H NMR.Taken 0.088 g of Pt(PF₃)₄ sample dissolved in 0.80 g of C₆D₆ containing0.03% (0.24 mg, 0.0027 mmol of SiMe₄. ¹H NMR (σ SiMe₄, ppm): 0.00 (s,6.28 mol. %, SiMe₄), 1.07 (t) and 2.39 (q) (18.64 mol %, Et-C₆H₅), 2.02(s, 11.41 mol. %, xylene), 2.14 (s, 63.67 mol. %, xylene), 6.97 (m,aromatic protons). If to recalculate mol % to wt. %, and count thatsolution contains 0.24 mg TMS, then the total amount of organiccompounds is 4.27 mg corresponding to 4.85 wt. % in 88 mg of Pt(PF₃)₄sample.

Example 5. Pt(PF₃)₄ Shelf Life

A shelf life study was performed during 12 weeks at room temperature.Pt(PF₃)₄ obtained in syntheses described in examples 3 and 4 and wasstored at room temperature in a 316 alloy Single-Ended Miniature SampleCylinder, volume 50 cm³ with the blind cap attached and inelectro-polished Stainless-Steel Miniature Canister (V=400 cm³) with theblind cap attached. Both containers were vacuum baked at approximately150° C. and 30-50 mTorr before introducing Pt(PF₃)₄. ¹⁹F and ¹H NMRspectra were measured for the neat liquid Pt(PF₃)₄ every 2 weeks,monitored Pt(PF₃)₄ assay and relative amount of impurities from ¹⁹F and¹H NMR spectra. The results of shelf life study are in Table 2.

TABLE 2 Package (Room Pt(PF₃)₄ Pt(PF₃)₄ Temperature) Material toad (g)assay* Impurities Hexadecane  50 mL 316 SS 45 99.74 ± 0.06% 0.26 ± 0.06%Not quantified (<10 ppm) 400 mL Electro- 160 99.77 ± 0.02% 0.22 ± 0.03%9.6 ± 0.5 ppm polished SS *Starting amount on day 1.

Pt(PF₃)₄ assay and relative amount of impurities is nearly similar inall experiments within 12 weeks. The deviation is higher for 316 SSsteel ampoule. These results demonstrate the stability of Pt(PF₃)₄ overtime. FIG. 4 is a graph for the Pt(PF₃)₄ assay and relative amount ofimpurities over time in a 400 mL electro-polished stainless-steelminiature canister at room temperature. The disclosed Pt(PF₃)₄ is aimedto use as a precursor for Pt-containing films in microelectronic devicesor in catalyst industries.

Comparative Example 1. Synthesis of Pt(PF₃)₄ Starting from K₂PtCl₆ Usingthe Recipes from Angew. Chem. Int. Ed. 1965, 4, 521 and RU2478576C2

Syntheses of Pt(PF₃)₄ according to the recipes from Angew. Chem. Int.Ed. 1965, 4, 521 and RU2478576C2 are shown in Table 3 below. Theexperiments are conducted with a commercially available high pressurereactor from Parr Instrument Company (Series 4540, 600 mL rated for 5000psig equipped with the standard impeller in experiments #10 and #12 andwith the U-type anchor stirrer designed for an efficient stirring ofsolids in b). The process of RU2478576C2 utilizes pure hydrogen and astep of drying after reduction, which requires costly safety equipmentand a long time, if removal of water from the system is ever possible byscaling. As shown in Table 3, #10 was done with the copper powder Cu of149 μm size (copper powder packed by vendor under argon and utilizedas). #11 and #12 were done with the copper powder Cu of 425 μm size(99.5% from Sigma-Aldrich). Synthesis of Pt(PF₃)₄ starting from PtCl₂(#12, Table 3) performed according to [Angew. Chem. Int. Ed. 1965, 4,521] was done with, where Cu prepared from Copper powder of <425 μm size(99.5% from Sigma-Aldrich). Pt(PF₃)₄ (in #10-12) is forming in low tomoderate yields.

Referring to Table 3, comparative examples performed on commerciallyavailable standard equipment, amounts of the starting materials K₂PtCl₆,PtCl₂, Cu were loaded in a reactor in a glove box with <0.5 ppm ofoxygen and moisture. The reactor sealed, connected to the vacuum line,vacuumed below 0.2 Torr, cooled below −79° C. and the required amount ofPF₃ introduced in reactions #10 to #12 at low temperature with stirring.Then the reactor warmed to room temperature and further to 105-130° C.and the content stirred under PF₃ pressure for 24 hours. Then reactorcontent cooled to 35-45° C. and the portion of gases (about 25-35%)directed in pre vacuumed trap (0.44 L, material stainless steel) cooledwith the dry ice-isopropanol mixture. The reactor closed, trap kept forabout 10 min and then the non-condensable gas directed in the secondtrap cooled with liquid nitrogen (6 L, material Aluminum). Transferlines and valves were warmed if cooled below 0° C. with the passing gas.After condensation of PF₃ portion in 6 L Al trap, vacuum applied to 6 LAl trap to get the pressure in trap below 1 Torr. Operation repeateduntil all PF₃ and Pt(PF₃)₄ were stripped from the reactor and collectedin two different traps. Then the trap with Pt(PF₃)₄ was reconnected to aseparate pre-vacuumed vessel (50 mL, stainless steel). The parent trapwith Pt(PF₃)₄ warmed to room temperature, while a receiving vesselcooled with liquid nitrogen and all Pt(PF₃)₄ distilled in the receivingvessel under a static vacuum. After distillation, the receiving vesselwarmed to room temperature and the residual PF₃ released through thescrubber. Yield of Pt(PF₃)₄ for each experiment shows a low to moderateyield, although RU2478576C2 claimed 60-95% yield. The low to moderateyield of Pt(PF₃)₄ obtained from RU2478576C2 recipe might be because of alack of solvent. Purity of Pt(PF₃)₄ is more than 97.9% in allexperiments according to ¹H, ¹⁹F NMR. As example, 9F NMR of neat productfrom experiment b) (σ CFCl₃, ppm): −11.5 (m, J(P-F)=1302 Hz, 97.9%,Pt(PF₃)₄), −34.4 (d, J(P-F)=1402 Hz, 0.2%, PF₃), −92.4 (d, J(P-F)=2035Hz, 2.0%, POF₃).

TABLE 3 Cu powder PF₃ Yield of Pt size pressure Pt(PF₃)₄ # reagent (g)(μm) (psig) (%, g) Observations 10 29.3 149 1552 1%, Solid baked in[K₂PtCl₆] 0.5 g one block, no stirring 11 54.1 425 2940 60%, Anchorstirrer. [K₂PtCl₆] 36.2 g K₂PtCl₆ partially sublimed on colder parts ofreactor and did not react further. 12 26.9 425 2350 20%, Standardimpeller. [PtCl₂] 11.1 g Poor mixing.

Example 6. Synthesis of Pt(PF₃)₄ Starting from K₂PtCl₆ in High PressureReactor with Hexadecane Solvent

K₂PtCl₆ (79.5 g, 0.16 mol), Cu (120.6 g, 1.9 mol), hexadecane (100 g)are loaded in a reactor (Parr Instrument Company, Series 4540, 600 mLrated for 5000 psig) in glove box. The reactor transferred and connectedto the vacuum line, vacuumed below 0.3 Torr and cooled below −79° C. and387 g (4.4 mol) of PF₃ introduced in the reactor. Then the reactorwarmed to room temperature, stirring started, the reactor further warmedto 120° C. and the content stirred under PF₃ pressure for 22 hours. Thenreactor content cooled to 35-45° C. and the portion of gases (about25-35%) directed in pre vacuumed trap (0.44 L, material stainless steel)cooled with the dry ice-isopropanol mixture. The reactor closed, trapkept for about 10 min and then the non-condensable gas directed in thesecond trap cooled with liquid nitrogen (6 L, material Aluminum).Transfer lines and valves were warmed if cooled below 0° C. with thepassing gas. After condensation of PF₃ portion in 6 L Al trap, vacuumapplied to 6 L Al trap to get the pressure in trap below 1 Torr.Operation repeated until all PF₃ and Pt(PF₃)₄ were stripped from thereactor and collected in two different traps. Then the trap withPt(PF₃)₄ was reconnected to a separate pre-vacuumed vessel (50 mL,stainless steel). The parent trap with Pt(PF₃)₄ warmed to roomtemperature, while a receiving vessel cooled with liquid nitrogen andall Pt(PF₃)₄ distilled in the receiving vessel under a static vacuum.After distillation, the receiving vessel warmed to room temperature andthe residual PF₃ released through the scrubber. Yield of Pt(PF₃)₄ is23.2 g, 25.9% from K₂PtCl₆. See Table 4, which lists the yields ofPt(PF₃)₄ starting from K₂PtCl₆, in the two reactions of this Example andthe above Comparative Example 1. #13 is from the above ComparativeExample 1 #11 and #14 was the result of this Example. Both reactions areat the same temperature and PF₃ pressure. Assay of Pt(PF₃)₄ byintegration of ¹⁹F NMR spectrum is 99.48%. ¹⁹F NMR of neat product fromexperiment b) (σ CFCl₃, ppm): −11.5 (m, J(P-F)=1302 Hz, 99.48%,Pt(PF₃)₄), −34.4 (d, J(P-F)=1402 Hz, 0.3%, PF₃), −92.4 (d, J(P-F)=2035Hz, 0.2%, POF₃).

TABLE 4 K₂PtCl₆ Yield of # (g) Hexadecane Pt(PF₃)₄ 13 54.1 — 60% (36.2g) 14 79.5 120 mL 26% (23.2 g)

The reason of the low yields of using PtCl₂ in Table 3 may be due toinefficient mixing of components, coating of metal with the metalchloride during the reaction and other factors accompanying the reactionstarting from two different solids and gas. The solution may be to shiftfrom a solid gas-system to the solution-solid system to have a bettermixing of components and more efficient interaction of componentsdissolved in the liquid phase with the suspended metal powder. However,no solution-solid system have been reported thus far because of theexpectation that solvent will undergo catalytic reaction with Ptprecursor or intermediate.

Although the subject matter described herein may be described in thecontext of illustrative implementations to process one or more computingapplication features/operations for a computing application havinguser-interactive components the subject matter is not limited to theseparticular embodiments. Rather, the techniques described herein may beapplied to any suitable type of user-interactive component executionmanagement methods, systems, platforms, and/or apparatus.

It will be understood that many additional changes in the details,materials, steps, and arrangement of parts, which have been hereindescribed and illustrated in order to explain the nature of theinvention, may be made by those skilled in the art within the principleand scope of the invention as expressed in the appended claims. Thus,the present invention is not intended to be limited to the specificembodiments in the examples given above and/or the attached drawings.

While embodiments of this invention have been shown and described,modifications thereof may be made by one skilled in the art withoutdeparting from the spirit or teaching of this invention. The embodimentsdescribed herein are exemplary only and not limiting. Many variationsand modifications of the composition and method are possible and withinthe scope of the invention. Accordingly, the scope of protection is notlimited to the embodiments described herein, but is only limited by theclaims which follow, the scope of which shall include all equivalents ofthe subject matter of the claims.

What is claimed is:
 1. A method for synthesizing Pt(PF₃)₄ (CAS#19529-53-4), the method comprising the steps of: dissolving a platinumcompound having a general formula, Pt(Hal)₂(PF₃)_(x), in an anhydroussolvent forming a Pt(Hal)₂(PF₃)_(x) solution, wherein Hal=F, Cl, Br orI, x=1, 2; adding a metal powder and excess amount of PF₃ into thePt(Hal)₂(PF₃)_(x) solution; and forming Pt(PF₃)₄ through a reactionbetween Pt(Hal)₂(PF₃)_(x), PF₃ and the metal powder under a reactioncondition.
 2. The method of claim 1, wherein the reaction conditionincludes a reaction temperature ranging from approximately from 30 to200° C.
 3. The method of claim 1, wherein the reaction conditionincludes a reaction pressure below approximately 300 psig.
 4. The methodof claim 1, wherein the anhydrous solvent has a boiling point higherthan 150° C.
 5. The method of claim 1, wherein the metal powder is acopper, zinc or aluminum powder.
 6. The method of claim 1, wherein themetal powder has a particle size ranging from 200-900 microns.
 7. Themethod of claim 1, further comprising the step of synthesizing theplatinum compound Pt(Hal)₂(PF₃)_(x) (Hal=F, Cl, Br or I; x=1, 2),wherein the synthesizing step comprises the steps of: dispersing aplatinum precursor having a general formula, Pt(Hal)₂, into theanhydrous solvent forming a suspension of Pt(Hal)₂, wherein Hal=F, Cl,Br or I; introducing PF₃ into the suspension of Pt(Hal)₂; and formingthe solution of the platinum compound Pt(Hal)₂(PF₃)_(x) (Hal=F, Cl, Bror I; x=1, 2) in the anhydrous solvent through a reaction of PF₃ andPt(Hal)₂.
 8. The method of claim 7, wherein the platinum precursorPt(Hal)₂ is anhydrous.
 9. The method of claim 1, wherein the platinumcompound Pt(Hal)₂(PF₃)_(x) (Hal=F, Cl, Br or I, x=1, 2) is anhydrous.10. The method of claim 1, further comprising the steps of: purifyingPt(PF₃)₄ in a trap made of metal under air and moisture free conditions;and storing the purified Pt(PF₃)₄ under air and moisture free conditionsin a container made of the metal, wherein the step of storing includesthe steps of removing moisture from the inner surface of the container;and electro-polishing the inner surface of the container, or passivatingthe container with PF₃ before introducing the purified Pt(PF₃)₄.
 11. Themethod of claim 10, wherein the metal for the trap and the metal for thecontainer are selected from carbon steel, stainless steel, or stainlesssteel 316 alloy, respectively.
 12. The method of claim 1, wherein theanhydrous solvent is a hydrocarbon solvent selected form anoxyhydrocarbon solvent having a general formula (C_(n)H_(2n+1))₂O (n≥1)and H₃C(O(CH₂)₂)OCH₃ (n≥1), an arene solvent having a general formula(C_(n)H_(2n+1))_(x)C₆H_(6−x) (x≥1, n≥1) or an alkane solvent having ageneral formula C_(n)H_(2n+2) (n≥1).
 13. The method of claim 1, whereina yield of Pt(PF₃)₄ is in a range of approximately 70-99.9%.
 14. Themethod of claim 1, wherein a purity of Pt(PF₃)₄ is approximately 90-99.9wt. % after purification.
 15. A method for synthesis and storage ofPt(PF₃)₄ (CAS #19529-53-4), the method comprising the steps of: g)forming a suspension of a platinum precursor Pt(Hal)₂, wherein Hal=F,Cl, Br or I, and a metal powder in an anhydrous solvent; h) introducingexcess amount of PF₃ into the suspension of Pt(Hal)₂ and the metalpowder; i) forming a soluble reaction intermediate Pt(Hal)₂(PF₃)_(x) inthe anhydrous solvent through a reaction between PF₃ and Pt(Hal)₂,wherein Hal=F, Cl, Br or I; x=1, 2, under a low pressure condition; j)forming Pt(PF₃)₄ from a reaction between Pt(Hal)₂(PF₃)_(x), the metalpowder and PF₃ in the anhydrous solvent; k) purifying Pt(PF₃)₄ under airand moisture free conditions in a trap made of metal; and l) storing thepurified Pt(PF₃)₄ under the air and moisture free conditions in acontainer made of the metal.
 16. The method of claim 15, wherein theplatinum precursor Pt(Hal)₂ is anhydrous PtCl₂.
 17. The method of claim15, wherein the anhydrous solvent has a boiling point higher than 150°C.
 18. The method of claim 15, wherein the anhydrous solvent is ahydrocarbon solvent selected form an oxyhydrocarbon solvent having ageneral formula (C_(n)H_(2n+1))₂O (n≥1) and H₃C(O(CH₂)₂)_(n)OCH₃ (n≥1),an arene solvent having a general formula (C_(n)H_(2n+1))_(x)C₆H_(6−x)(x≥1, n≥1) or an alkane solvent having a general formula C_(n)H_(2n+2)(n≥1).
 19. The method of claim 15, wherein a reaction temperature rangesfrom approximately 30-200° C.
 20. The method of claim 15, wherein thelow pressure condition is a pressure below approximately 300 psig. 21.The method of claim 15, wherein the metal powder is a copper, zinc oraluminum powder.
 22. The method of claim 15, wherein the metal powderhas a particle size ranging from 200-900 microns.
 23. The method ofclaim 15, wherein a yield of Pt(PF₃)₄ is in the range of approximately70-99.9%.
 24. The method of claim 15, wherein a purity of Pt(PF₃)₄ isapproximately 90-99.9 wt. % after purification.
 25. The method of claim15, wherein the metal for the trap and the metal for the container areselected from carbon steel, stainless steel, or stainless steel 316alloy, respectively.
 26. The method of claim 15, further comprising thesteps of: electro-polishing the inner surface of the container, orpassivating the container with PF₃ before introducing of the purifiedPt(PF₃)₄.
 27. A method for manufacture and storage of Pt(PF₃)₄ (CAS#19529-53-4), the method comprising the steps of: g) forming asuspension of a platinum precursor Pt(Cl)₂ in an anhydrous solventselected form xylene or hexadecane; h) introducing excess amount of PF₃into the suspension of Pt(Cl)₂ to form a solution of Pt(Cl)₂(PF₃)_(x)(x=1, 2) in the anhydrous solvent through a reaction between PF₃ andPt(Cl)₂; i) adding a copper powder into the solution of Pt(Cl)₂(PF₃)_(x)(x=1, 2); j) forming Pt(PF₃)₄ from a reaction between the copper powder,PF₃ and Pt(Cl)₂(PF₃)_(x) in the anhydrous solvent in a reduced PF₃pressure ranging from 20 to 300 psig and a reaction temperature rangingfrom 30-200° C.; k) purifying Pt(PF₃)₄ under air and moisture freeconditions in a trap made of stainless steel; and l) storing thepurified Pt(PF₃)₄ under the air and moisture free conditions in acontainer made of the stainless steel, wherein the inner surface of thecontainer is electro-polished or passivated with PF₃.
 28. The method ofclaim 27, wherein the copper powder has a particle size ranging from200-900 microns.